Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Consolidated Financial Statements include the accounts of the Parent and its subsidiaries. All intercompany accounts and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The Company prepares its Consolidated Financial Statements in conformity with GAAP. These principles require management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, together with amounts disclosed in the related notes to the Consolidated Financial Statements. Actual results and outcomes may differ from management’s estimates, judgments and assumptions. Significant estimates, judgments and assumptions used in these Consolidated Financial Statements include, but are not limited, to those related to revenues, accounts receivable and related allowances, contingencies, useful lives and recovery of long-term assets and intangible assets, income taxes and valuation allowances, stock-based compensation, business combinations, impairment analysis of goodwill, and restructuring reserves. These estimates, judgments, and assumptions are reviewed periodically and the effects of material revisions in estimates are reflected on the Consolidated Financial Statements prospectively from the date of the change in estimate.
Principles of Consolidation	Principles of Consolidation The Company determines whether investments in affiliates are a Variable Interest Entity (“VIE”) at the start of each new venture and when a reconsideration event has occurred. A reporting entity must consolidate a VIE if that reporting entity has a variable interest (or combination of variable interests) and is determined to be the primary beneficiary. The primary beneficiary has both the power to direct the activities of the VIE that most significantly impact the entity’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE.
Segment Reporting	Segment Reporting The Company has historically reported its activities in two reportable segments; (1) the Clinical Services segment and (2) the Pharma Services segment. In the second quarter of 2023, the Pharma Services segment was rebranded as the Advanced Diagnostics segment. Functions within the Clinical Services segment include oncology diagnostics, community-based oncology and pathology sales, patient engagement, and clinical decision support. Functions within the Advanced Diagnostics segment include pharma services, informatics, R&D, minimal residual disease, liquid biopsy and therapy selection business development.
Business Combinations	Business Combinations The Company accounts for acquisitions of entities over which control is obtained that include inputs and processes and have the ability to create outputs as business combinations. The tangible and identifiable intangible assets acquired and liabilities assumed in a business combination are recorded based on their estimated fair values as of the business combination date, including identifiable intangible assets which either arise from a contractual or legal right or are separable from goodwill. The Company bases the estimated fair value of identifiable intangible assets acquired in a business combination on independent third-party valuations that use information and assumptions provided by management, which consider estimates of inputs and assumptions that a market participant would use. Any excess purchase price over the estimated fair value assigned to the net tangible and identifiable intangible assets acquired less liabilities assumed is recorded to goodwill. The use of alternative valuation assumptions, including estimated revenue projections, growth rates, estimated cost savings, cash flows, discount rates, estimated useful lives, and probabilities surrounding the achievement of contingent milestones could result in different purchase price allocations and amortization expense in current and future periods. Transaction costs associated with acquisitions are expensed as incurred in general and administrative expenses in the Consolidated Statements of Operations. Results of operations and cash flows of acquired companies are included in the Company’s operating results from the date of acquisition.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying value of cash, certain cash equivalents, accounts receivable, net, other current assets, accounts payable, accrued expenses and other liabilities, and contract liabilities are considered reasonable estimates of their respective fair values due to their short-term nature. The Company measures its marketable securities at fair value on a recurring basis.
Cash and cash equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of ninety days or less to be cash equivalents. The Company maintains its cash and cash equivalents with financial institutions that the Company believes to be of high credit standing.
Marketable Securities	Marketable Securities The Company classifies all marketable securities as available-for-sale, including those with maturity dates beyond 12 months, and therefore these securities are classified within current assets on the Consolidated Balance Sheets as they are available to support current operational liquidity needs. Marketable securities are carried at fair value, with the unrealized holding gains and losses, net of income taxes, reflected in accumulated other comprehensive income until realized. The Company evaluates its marketable securities for other-than-temporary impairment on a quarterly basis. Unrealized losses are charged against net earnings when a decline in fair value is determined to be other-than-temporary. The Company reviews several factors to determine whether a loss is other-than-temporary, such as the length and extent of the fair value decline, the financial condition and near-term prospects of the issuer, and whether there is the intent to sell or will more likely than not be required to sell before the securities’ anticipated recovery. There were no other-than-temporary impairments for the years ended December 31, 2023, 2022 and 2021. Regardless of the intent to sell a security, the Company performs additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are recorded when the Company does not expect to receive cash flows sufficient to recover the amortized cost basis of a security. For the purposes of computing realized and unrealized gains and losses, cost and fair value are determined on a specific identification basis.
Accounts Receivable, net	Accounts Receivable, net Accounts receivable are reported for all Clinical Services payers based on the amount expected to be collected, which considers implicit price concessions. Implicit price concessions represent differences between amounts billed and the estimated consideration the Company expects to receive based on negotiated discounts, historical collection experience, and other anticipated adjustments, including anticipated payer denials. For Advanced Diagnostics, the Company negotiates billing schedules and payment terms on a contract-by-contract basis which can include payments based on certain milestones being achieved.
Inventories	Inventories Inventories consist principally of testing supplies and are valued at lower of cost or net realizable value, using the first-in, first-out method. The Company periodically reviews its inventories for excess or obsolescence and writes-down obsolete or otherwise unmarketable inventories to their estimated net realizable value.
Prepaid Assets	Prepaid Assets The Company records a prepaid expense for costs paid but not yet incurred. Those expected to be incurred within one year are recorded as prepaid assets within total current assets on the Consolidated Balance Sheets. Any costs expected to be incurred outside of one year are recorded as other assets within total non-current assets on the Consolidated Balance Sheets.
Other Current Assets	Other Current Assets As of December 31, 2023 and 2022, other current assets consisted primarily of receivables related to research and development (“R&D”) tax credits related to operations in the United Kingdom, contract assets and other non-trade receivables.
Property and Equipment, net	Property and Equipment, net Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed on the straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the related lease terms or their estimated useful lives. Costs incurred in connection with the development of internal-use software are capitalized in accordance with the accounting standard for internal-use software, and are amortized over the expected useful life of the software. The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of, and the related accumulated depreciation, are removed from the accounts and any resulting gain or loss is included in loss from operations. Repairs and maintenance costs are expensed as incurred and are included in cost of revenue, general and administrative expenses or R&D expenses, as appropriate in the Consolidated Statements of Operations.
Leases	Leases The Company leases corporate offices and laboratory spaces throughout the world, all of which are classified as operating leases expiring at various dates and generally having terms ranging from 1 to 20 years. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Some of the Company’s real estate lease agreements include options to either renew or early terminate the lease. Leases with renewal options allow the Company to extend the lease term typically between 1 and 5 years. When it is reasonably certain that the Company will exercise an option to renew or terminate a lease, these options are considered in determining the classification and measurement of the lease at lease commencement. Lease liabilities are recorded based on the present value of the future lease payments over the lease term and assessed as of the commencement date. Incentives received from landlords, such as reimbursements for tenant improvements and rent abatement periods, effectively reduce the total lease payments owed for leases. Certain real estate leases also include executory costs such as common area maintenance (non-lease component), as well as property insurance and property taxes (non-components). Lease payments, which may include lease components, non-lease components and non-components, are included in the measurement of the Company’s lease liabilities to the extent that such payments are either fixed amounts or variable amounts based on a rate or index (fixed in substance), as stipulated in the lease contract. Any actual costs in excess of such amounts are expensed as incurred as variable lease cost. The Company utilizes its incremental borrowing rate by lease term in order to calculate the present value of its future lease payments when the implicit rates in the leases agreements are not readily determinable. The discount rate represents a risk-adjusted rate on a secured basis and is the rate at which the Company would borrow funds to satisfy the scheduled lease liability payment streams commensurate with the lease term. Operating lease costs represent fixed lease payments recognized on a straight-line basis over the lease term. Operating lease costs include an immaterial amount of variable lease costs and are recorded in cost of revenue, general and administrative, sales and marketing, and R&D expenses (depending on the nature of the leased asset) in the Consolidated Statements of Operations.
Intangible Assets, net	Intangible Assets, net Intangible assets with determinable useful lives are recorded initially at acquired fair value or cost, less accumulated amortization. Each intangible asset with a determinable useful life is amortized over its estimated useful life using the straight-line method. The Company periodically reviews the estimated pattern in which the economic benefits will be consumed and adjusts the amortization period and pattern to match the estimate. Intangible assets with indefinite useful lives are recorded initially at fair value or cost and are tested annually for impairment or more frequently if management believes indicators of impairment exist.
Recoverability and Impairment of Long-Lived Assets	Recoverability and Impairment of Long-Lived Assets The Company reviews the recoverability of its long-lived assets (including definite-lived intangible assets) if events or changes in circumstances indicate the assets may be impaired. Evaluation of possible impairment is based on the Company’s ability to recover the asset from the expected future pretax cash flows (undiscounted and without interest charges) of the related operations. If the expected undiscounted pretax cash flows are less than the carrying amount of such asset, an impairment loss is recognized for the difference between the estimated fair value to the carrying amount of the asset.
Goodwill	Goodwill The Company evaluates goodwill on an annual basis in the fourth quarter, or more frequently if management believes indicators of impairment exist. Such indicators could include, but are not limited to, (1) a significant adverse change in legal factors or in business climate, (2) unanticipated competition, or (3) an adverse action or assessment by a regulator. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. If management concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, management performs a quantitative goodwill impairment test. The quantitative analysis is performed by comparing the fair value of the reporting unit to its carrying value. If the carrying value is greater than the estimate of fair value, an impairment loss will be recognized for the amount in which the carrying amount exceeds the reporting unit’s fair value. The Company estimates the fair values of its reporting units using a combination of the income, or discounted cash flows approach and the market approach, which utilizes comparable companies’ data.
Contingencies	Contingencies The Company accrues contingent losses when estimated impacts of various conditions, situations or circumstances involve uncertain outcomes. Contingent losses are recorded based on management judgment along with internal and external advice from legal counsel and/or technical consultants. Estimated losses from contingencies are recorded when both of the following conditions are met: (i) information available before the financial statements are issued (or available to be issued) indicates that it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements and (ii) the amount of loss can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, that amount shall be accrued. When no amount within the range is a better estimate than any other amount, however, the minimum amount in the range shall be accrued.
Debt Issuance Costs	Debt Issuance Costs Debt issuance costs related to convertible senior notes are recorded as deductions that net against the principal value of the debt and are amortized as interest expense over the life of the debt using the effective interest method. Debt issuance costs related to term loans are recorded as direct deductions from the carrying amount of the term loan and are amortized to interest expense over the life of the debt using the effective interest method. Debt issuance costs relating to line of credit arrangements are recorded as assets and amortized over the term of the credit arrangement regardless of whether any outstanding borrowing existed.
Stock-Based Compensation	Stock-based Compensation The Company measures compensation expense for stock-based awards to employees, non-employee contracted physicians, and directors based upon the awards’ initial grant-date fair values. Stock-based compensation expense for stock options, restricted stock awards, restricted stock units and performance awards is recorded over the requisite service period in general and administrative expenses on the Consolidated Statements of Operations. For awards with only a service condition, the Company expenses stock-based compensation using the straight-line method over the requisite service period for the entire award. For awards with a market condition, the Company expenses the grant date fair value at the target over the vesting period regardless of the value that the award recipients ultimately receive. The fair values of stock option grants are estimated as of the date of grant by applying the Black-Scholes option valuation model. The fair value of restricted stock with a market condition is estimated at the date of grant using the Monte Carlo simulation model. The Black-Scholes and Monte Carlo models incorporate assumptions as to stock price volatility, the expected life of options or restricted stock, a risk-free interest rate and dividend yield. The fair value of restricted stock without a market condition is estimated using the current market price of the Company’s common stock on the date of grant. Black-Scholes is affected by the stock price on the date of the grant as well as assumptions regarding a number of highly complex and subjective variables. These variables include the expected term of the option, expected risk-free interest rate, the expected volatility of common stock, and expected dividend yield; each of which is described below. The assumptions for expected term and expected volatility are the two assumptions that significantly affect the grant date fair value. Expected Term: The expected term of an option is determined using the simplified method under SAB 107 which represents the average between the vesting term and the contractual term. The Company utilizes the simplified method to determine the expected life of the options due to insufficient exercise activity during recent years. Risk-free Interest Rate: The risk-free interest rate used in the Black-Scholes model is based on the implied yield at the grant date of the U.S. Treasury zero-coupon issue with an equivalent term to the stock-based award being valued. Where the expected term of a stock-based award does not correspond with the term for which a zero coupon interest rate is quoted, the Company uses the nearest interest rate from available maturities. Expected Stock Price Volatility: The Company uses its own historical weekly volatility because that is more reflective of market conditions. Dividend Yield: Because the Company has never paid a dividend and does not expect to begin doing so in the foreseeable future, the Company assumed no dividend yield in valuing the stock-based awards. The fair value of the performance stock units (“PSUs”) granted during the year ended December 31, 2023 was estimated as of the grant date using a Monte Carlo simulation, which requires management to make assumptions regarding risk-free interest rates and volatility of the Company’s stock price. The Monte Carlo simulation incorporates the same assumptions as Black-Scholes as to stock price volatility, the risk-free interest rate and dividend yield. The Company utilized the expected life of the PSUs for the expected term of the award, as the vesting term and contractual term of the awards are identical.
Revenue Recognition	Revenue Recognition Clinical Services Revenue The Company’s specialized diagnostic services are performed based on a written test requisition form or an electronic equivalent. The performance obligation is satisfied and revenues are recognized once the diagnostic services have been performed and the results have been delivered to the ordering physician. These diagnostic services are billed to various payers, including client direct billing, commercial insurance, Medicare and other government payers, and patients. Revenue is recorded for all payers based on the amount expected to be collected, which considers implicit price concessions. Implicit price concessions represent differences between amounts billed and the estimated consideration the Company expects to receive based on negotiated discounts, historical collection experience, and other anticipated adjustments, including anticipated payer denials. Collection of consideration the Company expects to receive typically occurs within 90 to 120 days of billing for commercial insurance, Medicare and other governmental and self-pay patients and within 60 to 90 days of billing for client payers. Advanced Diagnostics Revenue The Company’s Advanced Diagnostics segment generally enters into contracts with pharmaceutical and biotech customers as well as other CRO to provide research and clinical trial services. Such services also include validation studies and assay development. The Company records revenue on a unit-of-service basis based on the number of units completed towards the satisfaction of a performance obligation. In addition, certain contracts include upfront fees and the revenue for those contracts is recognized over time as services are performed. Additional offerings within the Advanced Diagnostics portfolio includes Informatics, which involves the licensing of de-identified data to pharmaceutical and biotech customers in the form of either retrospective records or prospective deliveries of data. Informatics revenue is recognized at a point in time upon delivery of retrospective data or over time for prospective data feeds. The Company negotiates billing schedules and payment terms on a contract-by-contract basis, and contract terms generally provide for payments based on a unit-of-service arrangement. Amounts collected in advance of services being provided are deferred as contract liabilities on the Consolidated Balance Sheets. The associated revenue is recognized and the contract liability is reduced as the contracted services are subsequently performed. Contract assets are established for revenue recognized but not yet billed. These contract assets are reduced once the customer is invoiced and a corresponding receivable is recorded. Additionally, Advanced Diagnostics incurs sales commissions in the process of obtaining contracts with customers. Sales commissions that are payable upon contract award are recognized as assets and amortized over the expected contract term. The amortization of commission expense is based on the weighted average contract duration for all commissionable awards in the respective business in which the commission expense is paid, which approximates the period over which goods and services are transferred to the customer. For offerings with primarily short-term contracts, such as Informatics, the Company applies the practical expedient which allows costs to obtain a contract to be expensed when incurred, if the amortization period of the assets that would otherwise have been recognized is one year or less. Contract assets and capitalized commissions are included in other current assets and other assets on the Consolidated Balance Sheets. Most contracts are terminable by the customers, either immediately or according to advance notice terms specified within the contracts. All contracts require payment of fees to the Company for services rendered through the date of termination and may require payment for subsequent services necessary to conclude the study or close out the contract.
Cost of Revenue	Cost of Revenue Cost of revenue includes payroll and payroll related costs for performing tests, project management, depreciation of laboratory equipment and laboratory leasehold improvements, rent for laboratory facilities, laboratory reagents, probes and supplies, delivery and courier costs relating to the transportation of specimens to be tested, and amortization for acquired intangible assets. The expenses related to shipping specimens to the facilities for testing, includes costs incurred for contract couriers, commercial airline flights, and courier charges. The Company also incurs expenses returning samples and slides to its customers.
General and Administrative Expenses	General and Administrative Expenses General and administrative expenses consist of payroll and payroll related costs for the Company’s billing, finance, human resources, information technology, and other administrative personnel as well as stock-based compensation. The Company also includes professional services, facilities expense, IT infrastructure costs, depreciation, amortization, and other administrative-related costs in general and administrative expenses in the Consolidated Statements of Operations.
Research and Development	Research and Development Expenses R&D costs are expensed as incurred. R&D expenses consist of payroll and payroll related costs, laboratory supplies, depreciation of laboratory equipment, and costs for samples to complete validation studies. These expenses are primarily incurred to develop new genetic tests. R&D expenses are presented net of R&D tax and expenditure credits from the UK government, which are recognized over the period necessary to match the reimbursement with the related costs when it is probable that the Company has complied with any conditions attached and will receive the reimbursement. Sales and Marketing Expenses Sales and marketing expenses are primarily attributable to employee-related costs including sales management, sales representatives, sales and marketing consultants, and marketing and customer service personnel in the Clinical Services segment. Advertising costs are expensed at the time they are incurred and are deemed immaterial for the years ended December 31, 2023, 2022 and 2021.
Restructuring charges	Restructuring charges Restructuring charges relate to a restructuring program to improve execution and drive efficiency across the organization. Restructuring charges consist of severance and other employee costs, costs for optimizing the Company’s geographic presence, and consulting and other costs.
Income Taxes	Income Taxes We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and deferred tax liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine deferred tax assets and liabilities on the basis of the differences between financial statement and tax bases of the assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that included the enactment date. We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all positive and negative evidence. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the valuation allowance, which would reduce the provision for income taxes. The Company evaluates tax positions that have been taken or are expected to be taken in its tax returns and records a liability for uncertain tax positions, if deemed necessary. The Company follows a two-step approach to recognizing and measuring uncertain tax positions. First, tax positions are recognized if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon examination, including resolution of related appeals or litigation processes, if any. Second, the tax position is measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement. We recognize interest expense and penalties related to income tax matters, including unrecognized tax benefits, as a component of income tax expense.
Net Loss Income per Common Share	Net Loss per Common Share The Company calculates basic net (loss) income per share attributable to common stockholders by dividing net (loss) income by the weighted-average number of shares of common stock outstanding for the period. Diluted net (loss) income per share is computed using the weighted average number of common shares outstanding during the applicable period, plus the dilutive effect of potential common stock. Potential common stock consists of shares issuable pursuant to stock options and convertible notes, as well as nonvested restricted stock awards and performance stock units which are not considered outstanding with respect to the weighted average common shares outstanding in the calculation of basic net (loss) income per share. Potentially dilutive shares are determined by applying the treasury stock method to the Company’s outstanding stock options and restricted stock awards. Potentially dilutive shares issuable upon conversion of the 0.25% Convertible Senior Notes due 2028 and the 1.25% Convertible Senior Notes due 2025 are calculated using the if-converted method.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”). This update amends guidance to require that an entity (acquirer) recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Revenue from Contracts with Customers (Topic 606). At the acquisition date, an acquirer should account for the related revenue contracts in accordance with Topic 606 as if it had originated the contracts. ASU 2021-08 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption of the amendments is permitted including adoption in an interim period. If the Company early adopts in an interim period, the Company is required to apply the amendments (1) retrospectively to all business combinations for which the acquisition date occurs on or after the beginning of the fiscal year that includes the interim period of early application and (2) prospectively to all business combinations that occur on or after the date of initial application. The amendments in ASU 2021-08 should be applied prospectively to business combinations occurring on or after the effective date of the amendments. The Company adopted this standard as of January 1, 2023 and there was no impact on its Consolidated Financial Statements. Accounting Pronouncements Pending Adoption In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This update requires entities to consistently categorize and provide greater disaggregation of information in the rate reconciliation and to further disaggregate income taxes paid by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. ASU 2023-07 may be applied retrospectively or prospectively. The Company is currently evaluating the planned adoption date and the impact of this standard on its annual disclosures. In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This update requires entities to disclose significant segment expenses by reportable segment if they are regularly provided to the Chief Operating Decision Maker (CODM) and included in each reported measure of segment profit or loss and requires disclosure of other segment items by reportable segment and a description of its composition. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, with early adoption permitted. ASU 2023-07 should be applied retrospectively to all prior periods presented in the financial statements. The Company will adopt this pronouncement on January 1, 2024, and is currently evaluating the impact of this standard on its annual disclosures.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

The accompanying Consolidated Financial Statements include the accounts of the Parent and its subsidiaries. All intercompany accounts and balances have been eliminated in consolidation.

Use of Estimates

The Company prepares its Consolidated Financial Statements in conformity with GAAP. These principles require management to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, together with amounts disclosed in the related notes to the Consolidated Financial Statements. Actual results and outcomes may differ from management’s estimates, judgments and assumptions. Significant estimates, judgments and assumptions used in these Consolidated Financial Statements include, but are not limited, to those related to revenues, accounts receivable and related allowances, contingencies, useful lives and recovery of long-term assets and intangible assets, income taxes and valuation allowances, stock-based compensation, business combinations, impairment analysis of goodwill, and restructuring reserves. These estimates, judgments, and assumptions are reviewed periodically and the effects of material revisions in estimates are reflected on the Consolidated Financial Statements prospectively from the date of the change in estimate.

Principles of Consolidation

The Company determines whether investments in affiliates are a Variable Interest Entity (“VIE”) at the start of each new venture and when a reconsideration event has occurred. A reporting entity must consolidate a VIE if that reporting entity has a variable interest (or combination of variable interests) and is determined to be the primary beneficiary. The primary beneficiary has both the power to direct the activities of the VIE that most significantly impact the entity’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE.

Segment Reporting

The Company has historically reported its activities in two reportable segments; (1) the Clinical Services segment and (2) the Pharma Services segment. In the second quarter of 2023, the Pharma Services segment was rebranded as the Advanced Diagnostics segment. Functions within the Clinical Services segment include oncology diagnostics, community-based oncology and pathology sales, patient engagement, and clinical decision support. Functions within the Advanced Diagnostics segment include pharma services, informatics, R&D, minimal residual disease, liquid biopsy and therapy selection business development.

Business Combinations

The Company accounts for acquisitions of entities over which control is obtained that include inputs and processes and have the ability to create outputs as business combinations. The tangible and identifiable intangible assets acquired and liabilities assumed in a business combination are recorded based on their estimated fair values as of the business combination date, including identifiable intangible assets which either arise from a contractual or legal right or are separable from goodwill. The Company bases the estimated fair value of identifiable intangible assets acquired in a business combination on independent third-party valuations that use information and assumptions provided by management, which consider estimates of inputs and assumptions that a market participant would use. Any excess purchase price over the estimated fair value assigned to the net tangible and identifiable intangible assets acquired less liabilities assumed is recorded to goodwill. The use of alternative valuation assumptions, including estimated revenue projections, growth rates, estimated cost savings, cash flows, discount rates, estimated useful lives, and probabilities surrounding the achievement of contingent milestones could result in different

purchase price allocations and amortization expense in current and future periods. Transaction costs associated with acquisitions are expensed as incurred in general and administrative expenses in the Consolidated Statements of Operations. Results of operations and cash flows of acquired companies are included in the Company’s operating results from the date of acquisition.

Fair Value of Financial Instruments

The carrying value of cash, certain cash equivalents, accounts receivable, net, other current assets, accounts payable, accrued expenses and other liabilities, and contract liabilities are considered reasonable estimates of their respective fair values due to their short-term nature.

The Company measures its marketable securities at fair value on a recurring basis.

Cash and cash equivalents

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with an original maturity of ninety days or less to be cash equivalents. The Company maintains its cash and cash equivalents with financial institutions that the Company believes to be of high credit standing.

Marketable Securities

The Company classifies all marketable securities as available-for-sale, including those with maturity dates beyond 12 months, and therefore these securities are classified within current assets on the Consolidated Balance Sheets as they are available to support current operational liquidity needs.

Marketable securities are carried at fair value, with the unrealized holding gains and losses, net of income taxes, reflected in accumulated other comprehensive income until realized. The Company evaluates its marketable securities for other-than-temporary impairment on a quarterly basis. Unrealized losses are charged against net earnings when a decline in fair value is determined to be other-than-temporary. The Company reviews several factors to determine whether a loss is other-than-temporary, such as the length and extent of the fair value decline, the financial condition and near-term prospects of the issuer, and whether there is the intent to sell or will more likely than not be required to sell before the securities’ anticipated recovery. There were no other-than-temporary impairments for the years ended December 31, 2023, 2022 and 2021. Regardless of the intent to sell a security, the Company performs additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are recorded when the Company does not expect to receive cash flows sufficient to recover the amortized cost basis of a security.

For the purposes of computing realized and unrealized gains and losses, cost and fair value are determined on a specific identification basis.

Accounts Receivable, net

Accounts receivable are reported for all Clinical Services payers based on the amount expected to be collected, which considers implicit price concessions. Implicit price concessions represent differences between amounts billed and the estimated consideration the Company expects to receive based on negotiated discounts, historical collection experience, and other anticipated adjustments, including anticipated payer denials.

For Advanced Diagnostics, the Company negotiates billing schedules and payment terms on a contract-by-contract basis which can include payments based on certain milestones being achieved.

Inventories

Inventories consist principally of testing supplies and are valued at lower of cost or net realizable value, using the first-in, first-out method. The Company periodically reviews its inventories for excess or obsolescence and writes-down obsolete or otherwise unmarketable inventories to their estimated net realizable value.

Prepaid Assets

The Company records a prepaid expense for costs paid but not yet incurred. Those expected to be incurred within one year are recorded as prepaid assets within total current assets on the Consolidated Balance Sheets. Any costs expected to be incurred outside of one year are recorded as other assets within total non-current assets on the Consolidated Balance Sheets.

Other Current Assets

As of December 31, 2023 and 2022, other current assets consisted primarily of receivables related to research and development (“R&D”) tax credits related to operations in the United Kingdom, contract assets and other non-trade receivables.

Property and Equipment, net

Property and equipment are recorded at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed on the straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the related lease terms or their estimated useful lives. Costs incurred in connection with the development of internal-use software are capitalized in accordance with the accounting standard for internal-use software, and are amortized over the expected useful life of the software.

The Company periodically reviews the estimated useful lives of property and equipment. Changes to the estimated useful lives are recorded prospectively from the date of the change. Upon retirement or sale, the cost of the assets disposed of, and the related accumulated depreciation, are removed from the accounts and any resulting gain or loss is included in loss from operations. Repairs and maintenance costs are expensed as incurred and are included in cost of revenue, general and administrative expenses or R&D expenses, as appropriate in the Consolidated Statements of Operations.

Leases

The Company leases corporate offices and laboratory spaces throughout the world, all of which are classified as operating leases expiring at various dates and generally having terms ranging from 1 to 20 years. Leases with an initial term of 12 months or less are not recorded on the balance sheet.

Some of the Company’s real estate lease agreements include options to either renew or early terminate the lease. Leases with renewal options allow the Company to extend the lease term typically between 1 and 5 years. When it is reasonably certain that the Company will exercise an option to renew or terminate a lease, these options are considered in determining the classification and measurement of the lease at lease commencement.

Lease liabilities are recorded based on the present value of the future lease payments over the lease term and assessed as of the commencement date. Incentives received from landlords, such as reimbursements for tenant improvements and rent abatement periods, effectively reduce the total lease payments owed for leases.

Certain real estate leases also include executory costs such as common area maintenance (non-lease component), as well as property insurance and property taxes (non-components). Lease payments, which may include lease components, non-lease components and non-components, are included in the measurement of the Company’s lease liabilities to the extent that such payments are either fixed amounts or variable amounts based on a rate or index (fixed in substance), as stipulated in the lease contract. Any actual costs in excess of such amounts are expensed as incurred as variable lease cost.

The Company utilizes its incremental borrowing rate by lease term in order to calculate the present value of its future lease payments when the implicit rates in the leases agreements are not readily determinable. The discount rate represents a risk-adjusted rate on a secured basis and is the rate at which the Company would borrow funds to satisfy the scheduled lease liability payment streams commensurate with the lease term.

Operating lease costs represent fixed lease payments recognized on a straight-line basis over the lease term. Operating lease costs include an immaterial amount of variable lease costs and are recorded in cost of revenue, general and administrative, sales and marketing, and R&D expenses (depending on the nature of the leased asset) in the Consolidated Statements of Operations.

Intangible Assets, net

Intangible assets with determinable useful lives are recorded initially at acquired fair value or cost, less accumulated amortization. Each intangible asset with a determinable useful life is amortized over its estimated useful life using the straight-line method. The Company periodically reviews the estimated pattern in which the economic benefits will be consumed and adjusts the amortization period and pattern to match the estimate. Intangible assets with indefinite useful lives are recorded initially at fair value or cost and are tested annually for impairment or more frequently if management believes indicators of impairment exist.

Recoverability and Impairment of Long-Lived Assets

The Company reviews the recoverability of its long-lived assets (including definite-lived intangible assets) if events or changes in circumstances indicate the assets may be impaired. Evaluation of possible impairment is based on the Company’s ability to recover the asset from the expected future pretax cash flows (undiscounted and without interest charges) of the related operations. If the expected undiscounted pretax cash flows are less than the carrying amount of such asset, an impairment loss is recognized for the difference between the estimated fair value to the carrying amount of the asset.

Goodwill

The Company evaluates goodwill on an annual basis in the fourth quarter, or more frequently if management believes indicators of impairment exist. Such indicators could include, but are not limited to, (1) a significant adverse change in legal factors or in business climate, (2) unanticipated competition, or (3) an adverse action or assessment by a regulator. The Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. If management concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, management performs a quantitative goodwill impairment test. The quantitative analysis is performed by comparing the fair value of the reporting unit to its carrying value. If the carrying value is greater than the estimate of fair value, an impairment loss will be recognized for the amount in which the carrying amount exceeds the reporting unit’s fair value. The Company estimates the fair values of its reporting units using a combination of the income, or discounted cash flows approach and the market approach, which utilizes comparable companies’ data.

Contingencies

The Company accrues contingent losses when estimated impacts of various conditions, situations or circumstances involve uncertain outcomes. Contingent losses are recorded based on management judgment along with internal and external advice from legal counsel and/or technical consultants. Estimated losses from contingencies are recorded when both of the following conditions are met: (i) information available before the financial statements are issued (or available to be issued) indicates that it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements and (ii) the amount of loss can be reasonably estimated. If some amount within a range of loss appears at the time to be a better estimate than any other amount within the range, that amount shall be accrued. When no amount within the range is a better estimate than any other amount, however, the minimum amount in the range shall be accrued.

Debt Issuance Costs

Debt issuance costs related to convertible senior notes are recorded as deductions that net against the principal value of the debt and are amortized as interest expense over the life of the debt using the effective interest method. Debt issuance costs related to term loans are recorded as direct deductions from the carrying amount of the term loan and are amortized to interest expense over the life of the debt using the effective interest method. Debt issuance costs relating to line of credit arrangements are recorded as assets and amortized over the term of the credit arrangement regardless of whether any outstanding borrowing existed.

Stock-Based Compensation

Stock-based Compensation

The Company measures compensation expense for stock-based awards to employees, non-employee contracted physicians, and directors based upon the awards’ initial grant-date fair values. Stock-based compensation expense for stock options, restricted stock awards, restricted stock units and performance awards is recorded over the requisite service period in general and administrative expenses on the Consolidated Statements of Operations. For awards with only a service condition, the Company expenses stock-based compensation using the straight-line method over the requisite service period for the entire award. For awards with a market condition, the Company expenses the grant date fair value at the target over the vesting period regardless of the value that the award recipients ultimately receive. The fair values of stock option grants are estimated as of the date of grant by applying the Black-Scholes option valuation model. The fair value of restricted stock with a market condition is estimated at the date of grant using the Monte Carlo simulation model. The Black-Scholes and Monte Carlo models incorporate assumptions as to stock price volatility, the expected life of options or restricted stock, a risk-free interest

rate and dividend yield. The fair value of restricted stock without a market condition is estimated using the current market price of the Company’s common stock on the date of grant.

Black-Scholes is affected by the stock price on the date of the grant as well as assumptions regarding a number of highly complex and subjective variables. These variables include the expected term of the option, expected risk-free interest rate, the expected volatility of common stock, and expected dividend yield; each of which is described below. The assumptions for expected term and expected volatility are the two assumptions that significantly affect the grant date fair value.

Expected Term: The expected term of an option is determined using the simplified method under SAB 107 which represents the average between the vesting term and the contractual term. The Company utilizes the simplified method to determine the expected life of the options due to insufficient exercise activity during recent years.

Risk-free Interest Rate: The risk-free interest rate used in the Black-Scholes model is based on the implied yield at the grant date of the U.S. Treasury zero-coupon issue with an equivalent term to the stock-based award being valued. Where the expected term of a stock-based award does not correspond with the term for which a zero coupon interest rate is quoted, the Company uses the nearest interest rate from available maturities.

Expected Stock Price Volatility: The Company uses its own historical weekly volatility because that is more reflective of market conditions.

Dividend Yield: Because the Company has never paid a dividend and does not expect to begin doing so in the foreseeable future, the Company assumed no dividend yield in valuing the stock-based awards.

The fair value of the performance stock units (“PSUs”) granted during the year ended December 31, 2023 was estimated as of the grant date using a Monte Carlo simulation, which requires management to make assumptions regarding risk-free interest rates and volatility of the Company’s stock price. The Monte Carlo simulation incorporates the same assumptions as Black-Scholes as to stock price volatility, the risk-free interest rate and dividend yield. The Company utilized the expected life of the PSUs for the expected term of the award, as the vesting term and contractual term of the awards are identical.

Revenue Recognition

Clinical Services Revenue

The Company’s specialized diagnostic services are performed based on a written test requisition form or an electronic equivalent. The performance obligation is satisfied and revenues are recognized once the diagnostic services have been performed and the results have been delivered to the ordering physician. These diagnostic services are billed to various payers, including client direct billing, commercial insurance, Medicare and other government payers, and patients. Revenue is recorded for all payers based on the amount expected to be collected, which considers implicit price concessions. Implicit price concessions represent differences between amounts billed and the estimated consideration the Company expects to receive based on negotiated discounts, historical collection experience, and other anticipated adjustments, including anticipated payer denials. Collection of consideration the Company expects to receive typically occurs within 90 to 120 days of billing for commercial insurance, Medicare and other governmental and self-pay patients and within 60 to 90 days of billing for client payers.

Advanced Diagnostics Revenue

The Company’s Advanced Diagnostics segment generally enters into contracts with pharmaceutical and biotech customers as well as other CRO to provide research and clinical trial services. Such services also include validation studies and assay development. The Company records revenue on a unit-of-service basis based on the number of units completed towards the satisfaction of a performance obligation. In addition, certain contracts include upfront fees and the revenue for those contracts is recognized over time as services are performed.

Additional offerings within the Advanced Diagnostics portfolio includes Informatics, which involves the licensing of de-identified data to pharmaceutical and biotech customers in the form of either retrospective records or prospective deliveries of data. Informatics revenue is recognized at a point in time upon delivery of retrospective data or over time for prospective data feeds. The Company negotiates billing schedules and payment terms on a contract-by-contract basis, and contract terms generally provide for payments based on a unit-of-service arrangement.

Amounts collected in advance of services being provided are deferred as contract liabilities on the Consolidated Balance Sheets. The associated revenue is recognized and the contract liability is reduced as the contracted services are subsequently performed. Contract assets are established for revenue recognized but not yet billed. These contract assets are reduced once the customer is invoiced and a corresponding receivable is recorded. Additionally, Advanced Diagnostics incurs sales commissions in the process of obtaining contracts with customers. Sales commissions that are payable upon contract award

are recognized as assets and amortized over the expected contract term. The amortization of commission expense is based on the weighted average contract duration for all commissionable awards in the respective business in which the commission expense is paid, which approximates the period over which goods and services are transferred to the customer. For offerings with primarily short-term contracts, such as Informatics, the Company applies the practical expedient which allows costs to obtain a contract to be expensed when incurred, if the amortization period of the assets that would otherwise have been recognized is one year or less. Contract assets and capitalized commissions are included in other current assets and other assets on the Consolidated Balance Sheets.

Most contracts are terminable by the customers, either immediately or according to advance notice terms specified within the contracts. All contracts require payment of fees to the Company for services rendered through the date of termination and may require payment for subsequent services necessary to conclude the study or close out the contract.

Cost of Revenue

Cost of revenue includes payroll and payroll related costs for performing tests, project management, depreciation of laboratory equipment and laboratory leasehold improvements, rent for laboratory facilities, laboratory reagents, probes and supplies, delivery and courier costs relating to the transportation of specimens to be tested, and amortization for acquired intangible assets. The expenses related to shipping specimens to the facilities for testing, includes costs incurred for contract couriers, commercial airline flights, and courier charges. The Company also incurs expenses returning samples and slides to its customers.

General and Administrative Expenses

General and administrative expenses consist of payroll and payroll related costs for the Company’s billing, finance, human resources, information technology, and other administrative personnel as well as stock-based compensation. The Company also includes professional services, facilities expense, IT infrastructure costs, depreciation, amortization, and other administrative-related costs in general and administrative expenses in the Consolidated Statements of Operations.

Research and Development

Research and Development Expenses

R&D costs are expensed as incurred. R&D expenses consist of payroll and payroll related costs, laboratory supplies, depreciation of laboratory equipment, and costs for samples to complete validation studies. These expenses are primarily incurred to develop new genetic tests. R&D expenses are presented net of R&D tax and expenditure credits from the UK government, which are recognized over the period necessary to match the reimbursement with the related costs when it is probable that the Company has complied with any conditions attached and will receive the reimbursement.

Sales and Marketing Expenses

Sales and marketing expenses are primarily attributable to employee-related costs including sales management, sales representatives, sales and marketing consultants, and marketing and customer service personnel in the Clinical Services segment. Advertising costs are expensed at the time they are incurred and are deemed immaterial for the years ended December 31, 2023, 2022 and 2021.

Restructuring charges

Restructuring charges relate to a restructuring program to improve execution and drive efficiency across the organization. Restructuring charges consist of severance and other employee costs, costs for optimizing the Company’s geographic presence, and consulting and other costs.

Income Taxes

We account for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and deferred tax liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, we determine deferred tax assets and liabilities on the basis of the differences between financial statement and tax bases of the assets and liabilities by using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that included the enactment date.

We recognize deferred tax assets to the extent that we believe that these assets are more likely than not to be realized. In making such a determination, we consider all positive and negative evidence. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the valuation allowance, which would reduce the provision for income taxes.

The Company evaluates tax positions that have been taken or are expected to be taken in its tax returns and records a liability for uncertain tax positions, if deemed necessary. The Company follows a two-step approach to recognizing and measuring uncertain tax positions. First, tax positions are recognized if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon examination, including resolution of related appeals or litigation processes, if any. Second, the tax position is measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement.

We recognize interest expense and penalties related to income tax matters, including unrecognized tax benefits, as a component of income tax expense.

Net Loss Income per Common Share

Net Loss per Common Share

The Company calculates basic net (loss) income per share attributable to common stockholders by dividing net (loss) income by the weighted-average number of shares of common stock outstanding for the period. Diluted net (loss) income per share is computed using the weighted average number of common shares outstanding during the applicable period, plus the dilutive effect of potential common stock. Potential common stock consists of shares issuable pursuant to stock options and convertible notes, as well as nonvested restricted stock awards and performance stock units which are not considered outstanding with respect to the weighted average common shares outstanding in the calculation of basic net (loss) income per share. Potentially dilutive shares are determined by applying the treasury stock method to the Company’s outstanding stock options and restricted stock awards. Potentially dilutive shares issuable upon conversion of the 0.25% Convertible Senior Notes due 2028 and the 1.25% Convertible Senior Notes due 2025 are calculated using the if-converted method.

Recent Accounting Pronouncements

In October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”). This update amends guidance to require that an entity (acquirer) recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Revenue from Contracts with Customers (Topic 606). At the acquisition date, an acquirer should account for the related revenue contracts in accordance with Topic 606 as if it had originated the contracts. ASU 2021-08 is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption of the amendments is permitted including adoption in an interim period. If the Company early adopts in an interim period, the Company is required to apply the amendments (1) retrospectively to all business combinations for which the acquisition date occurs on or after the beginning of the fiscal year that includes the interim period of early application and (2) prospectively to all business combinations that occur on or after the date of initial application. The amendments in ASU 2021-08 should be applied prospectively to business combinations occurring on or after the effective date of the amendments. The Company adopted this standard as of January 1, 2023 and there was no impact on its Consolidated Financial Statements.

Accounting Pronouncements Pending Adoption

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This update requires entities to consistently categorize and provide greater disaggregation of information in the rate reconciliation and to further disaggregate income taxes paid by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. ASU 2023-07 may be applied retrospectively or prospectively. The Company is currently evaluating the planned adoption date and the impact of this standard on its annual disclosures.

In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This update requires entities to disclose significant segment expenses by reportable segment if they are regularly provided to the Chief Operating Decision Maker (CODM) and included in each reported measure of segment profit or loss and requires disclosure of other segment items by reportable segment and a description of its composition. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, with early adoption permitted. ASU 2023-07 should be applied retrospectively to all prior periods presented in the financial statements. The Company will adopt this pronouncement on January 1, 2024, and is currently evaluating the impact of this standard on its annual disclosures.