Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

Basis of Presentation

Our unaudited condensed consolidated financial statements include the accounts of Castle Biosciences, Inc. and our wholly owned subsidiaries and have been prepared in conformity with accounting principles generally accepted in the United States of America (‘‘U.S. GAAP’’). All intercompany accounts and transactions have been eliminated in consolidation.

Unaudited Interim Financial Information

The accompanying condensed consolidated balance sheet as of March 31, 2023 and the condensed consolidated statements of operations, the condensed consolidated statements of comprehensive loss, the condensed consolidated statements of stockholders’ equity and the condensed consolidated statements of cash flows for the three months ended March 31, 2023 and 2022 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of our consolidated financial position as of March 31, 2023 and the results of our consolidated operations and our consolidated cash flows for the three months ended March 31, 2023 and 2022. The financial data and other information disclosed in these notes related to the three months ended March 31, 2023 and 2022 are also unaudited. The results for the three months ended March 31, 2023 are not necessarily indicative of results to be expected for the year ending December 31, 2023, any other interim periods, or any future year or period. The balance sheet as of December 31, 2022 included herein was derived from the audited financial statements as of that date. Certain disclosures have been condensed or omitted from the unaudited interim consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K (the "2022 Form 10-K") for the year ended December 31, 2022 filed with the Securities and Exchange Commission (“SEC”) on February 28, 2023.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates include revenue recognition, the valuation of stock-based compensation, assessing future tax exposure and the realizability of deferred tax assets, the useful lives and recoverability of long-lived assets, the goodwill impairment test, the valuation of acquired intangible assets and the valuation of contingent consideration and other contingent liabilities. We base these estimates on historical and anticipated results, trends, and various other assumptions that we believe are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recorded revenues and expenses that are not readily apparent from other sources. Actual results could differ from those estimates and assumptions.

Cash and Cash Equivalents including Concentrations of Credit Risk

Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less. Our cash equivalents consist of money market funds, which are not insured by the Federal Deposit Insurance Corporation (“FDIC”), that are primarily invested in short-term U.S. government obligations. Cash deposits at financial institutions may exceed the amount of insurance provided by the FDIC. Management believes that we are not exposed to significant credit risk on our cash deposits due to the financial position of the financial institutions in which deposits are held.

Marketable Investment Securities

All debt securities are recognized in accordance with Financial Accounting Standards Board (‘‘FASB’’) Accounting Standards Codification (‘‘ASC’’) Topic 320, Investments-Debt Securities (‘‘ASC 320’’). Management determines the appropriate classification of securities at the time of purchase and re-evaluates such determination at each balance sheet date. All debt securities are classified as available-for-sale and are recorded at fair value in accordance with ASC 320. We recognize the unrealized gains and losses related to changes in fair value as a separate component of accumulated other comprehensive loss within total stockholders’ equity, net of any related deferred income tax effects, on our condensed consolidated balance sheets. Premiums or discounts from par value are amortized to interest income over the life of the underlying investment. Realized gains and losses on available-for-sale securities are calculated at the individual security level and included in interest income in the condensed consolidated statements of operations. Impairments of available-for-sale debt securities, if any, are recorded in our unaudited condensed consolidated statements of operations. See Notes 5 and 10 for further details.

Revenue Recognition

In accordance with ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”), we follow a five-step process to recognize revenues: (1) identify the contract with the customer, (2) identify the performance obligations, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations and (5) recognize revenues when the performance obligations are satisfied. We have determined that we have a contract with the patient when the treating clinician orders the test. Our contracts generally contain a single performance obligation, which is the delivery of the test report, and we satisfy our performance obligation at a point in time upon the delivery of the test report to the treating clinician, at which point we can bill for the report. The amount of revenue recognized reflects the amount of consideration to which we expect to be entitled, or the transaction price, and considers the effects of variable consideration. See Note 3 for further details.

Accounts Receivable and Allowance for Credit Losses

We classify accounts receivable balances that are expected to be paid more than one year from the consolidated balance sheet date as noncurrent assets. The estimated timing of payment utilized as a basis for classification as noncurrent is determined by analyses of historical payor-specific payment experience, adjusted for known factors that are expected to change the timing of future payments.

We accrue an allowance for credit losses against our accounts receivable based on management’s current estimate of amounts that will not be collected. Management’s estimates are typically based on historical loss information adjusted for current conditions. We generally do not perform evaluations of customers’ financial condition and generally do not require collateral. Historically, our credit losses have not been significant. The allowance for credit losses was zero as of March 31, 2023 and December 31, 2022. Adjustments for implicit price concessions attributable to variable consideration, as discussed below, are incorporated into the measurement of the accounts receivable balances and are not part of the allowance for credit losses.

Accrued Compensation

We accrue for liabilities under discretionary employee and executive bonus plans. Our estimated compensation liabilities are based on progress against corporate objectives approved by our board of directors, compensation levels of eligible individuals and target bonus percentage levels. Our board of directors reviews and evaluates the performance against these objectives and ultimately determines the actual achievement levels attained. We also accrue for liabilities under employee sales incentive bonus plans with accruals based on performance achieved to date compared to established targets. As of March 31, 2023 and December 31, 2022, we accrued approximately $5,858,000 and $18,209,000, respectively, for liabilities associated with these bonus plans. These amounts are classified as current or noncurrent accrued liabilities in the unaudited condensed consolidated balance sheets based on the expected timing of payment.

Stock-Based Compensation

Stock-based compensation expense for equity instruments issued to employees is measured based on the grant-date fair value of the awards. The fair value of employee stock options and offerings under the 2019 Employee Stock Purchase Plan (the “ESPP”) are estimated on the date of grant using the Black-Scholes option-pricing valuation model. For restricted stock units (“RSUs”) and performance-based restricted stock units (“PSUs”), the fair value is equal to the closing price of our common stock on the date of grant. For awards with graded vesting and only service conditions, we recognize compensation costs on a straight-line basis over the requisite service period of the awards. For options and RSUs, the requisite service period is generally the awards’ vesting period (typically four years). PSUs vest upon the achievement of certain performance conditions and the provision of service with us through a specified period. Accruals of compensation cost for PSUs are based on the probable outcome of the performance conditions and are reassessed each reporting period. We recognize compensation cost for PSUs separately for each vesting tranche on a ratable basis over the requisite service period. The requisite service period for PSUs is based on an analysis of vesting requirements and performance conditions for the particular award. Certain employees are entitled to acceleration of vesting of a portion of their awards upon retirement, subject to age, years of service and notice requirements. In these cases, the requisite service period takes into consideration the employee’s retirement eligibility, and is reassessed at each reporting date. For the ESPP, the requisite service period is generally the period of time from the offering date to the purchase date. Forfeitures are accounted for as they occur.

Comprehensive Loss

Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss is made up of net loss plus net unrealized gain (loss) on marketable investment securities, which is our only other item of other comprehensive income (loss).