In the opinion of management, the accompanying unaudited consolidated financial statements of First Interstate BancSystem, Inc., First Interstate Bank (“FIB”), and its other subsidiaries (together, the “Company”) contain all adjustments (all of which are of a normal recurring nature) necessary to present fairly the financial position of the Company at September 30, 2020 and December 31, 2019, the results of operations and changes in stockholders’ equity for each of the three and nine month periods ended September 30, 2020 and 2019, and cash flows for each of the nine month periods ended September 30, 2020 and 2019, in conformity with U.S. generally accepted accounting principles (“GAAP”). The balance sheet information at December 31, 2019 is derived from audited consolidated financial statements. Certain reclassifications, none of which were material, have been made to conform prior year financial statements to the September 30, 2020 presentation. These reclassifications did not change previously reported net income or stockholders’ equity.

These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. Operating results for the three and nine months ended September 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020.

On January 1, 2020, the Company adopted Accounting Standards Codification (“ASC”) 326, Measurement of Credit Losses on Financial Instruments (“ASC 326”), and replaced the historically used incurred loss methodology with an expected loss methodology that is referred to as the Current Expected Credit Loss (CECL) methodology. The measurement of expected credit losses under the CECL methodology is applicable to financial assets measured at amortized cost, including loans held for investment receivables and held-to-maturity debt securities. It also applies to off-balance sheet credit exposures not accounted for as insurance (loan commitments, standby letters of credit, financial guarantees, and other similar instruments) and net investments in leases recognized by a lessor in accordance with Topic 842 on leases. In addition, ASC 326 made changes to the accounting for available-for-sale debt securities. One such change is to require credit losses to be presented as an allowance rather than as a write-down on available-for-sale debt securities that management does not intend to sell or believes that it is more likely than not they will be required to sell. See “Note 16 - Recent Authoritative Accounting Guidance” included in this report for additional details.



	Pre-ASC 326 Adoption		Post-ASC 326 Adoption		Impact of ASC 326 Adoption
Assets:
Allowance for credit losses on HTM securities	$	—	$	—	$	—
Allowance for credit losses on loans held for investment	73.0		103.0		30.0
Liabilities:
Off-balance sheet credit exposures	—		2.3		2.3
Deferred tax liability	26.7		18.5		(8.2)
Equity:
Retained earnings	953.6		929.5		(24.1)

Investments in debt securities that the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and carried at amortized cost. Investments in debt securities that may be sold in response to or in anticipation of changes in interest rates and resulting prepayment risk, or other factors, are classified as available-for-sale and carried at fair value. The unrealized gains and losses on these securities are reported, net of applicable income taxes, as a separate component of stockholders’ equity and comprehensive income. Management determines the appropriate classification of securities at the time of purchase and at each reporting date management reassesses the appropriateness of the classification.

The amortized cost of debt securities classified as held-to-maturity or available-for-sale is adjusted for accretion of discounts to maturity and amortization of premiums over the estimated average life of the security, without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated, or in the case of callable securities, through the first call date, using the effective yield method. Such amortization and accretion is included in interest income. Realized gains and losses on sales are recorded on the trade date in investment securities gains and losses and determined using the specific identification method.

Allowance for Credit Losses - Held-to-Maturity Securities: Management measures expected credit losses on held-to-maturity debt securities on a collective basis by major security type. Accrued interest receivable on held-to-maturity debt securities is excluded from the estimate of credit losses. The estimate of expected credit losses considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts.

State, county and municipal securities. Municipal bonds issued by municipal governments within the U.S. These types of securities are primarily composed of general obligation bonds, or municipal bonds backed by the credit and taxing power of the issuing jurisdiction and revenue obligation bonds, or municipal bonds that are financed by income-producing projects and are secured by a specified source of revenue. Municipal issues shall have at least an "A-" rating by Moody's and/or Standard and Poor’s, or equivalent creditworthiness must be established prior to purchase. All non-rated or private placement securities must be analyzed and approved by the Company’s Credit Department and documented prior to purchase.

Obligations of U.S. government agencies and entities. Securities held by the Company are primarily issued by The Federal Home Loan Mortgage Corporation, known as Freddie Mac, and The Federal National Mortgage Association, Fannie Mae, which are implicitly guaranteed by the U.S. government and are consistently highly rated by major rating agencies with very little risk to default.

U.S. agency residential mortgage backed securities and Collateralized Mortgage Obligations. Residential mortgage backed securities held by the Company are primarily issued by U.S. government agencies and entities. These securities are either explicitly or implicitly guaranteed by the U.S. government, are consistently highly rated by major rating agencies with very little risk to default. Collateralized mortgage obligations include agency and non-agency residential securities which currently carry ratings no lower than investment grade “BBB-” and pass the federal financial institutions examinations test (Collateral Mortgage Obligation volatility test) at the time of purchase.

Corporate securities. Securities held by the Company are primarily comprised of corporate bonds (both senior and subordinated-debt) issued by a firm or public entity which currently carry ratings no lower than investment grade “BBB-” or better by Moody’, Standard and Poor’s, or Kroll rating agencies. All corporate subordinated-debt securities are analyzed and approved by the Company prior to purchase.

Allowance for Credit Losses - Available-For-Sale Securities: For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security's amortized cost basis is written down to fair value through income. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company performs a qualitative assessment as to whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income.

Changes in the allowance for credit losses are recorded as provision for (or reversal of) credit loss expense. Losses are charged against the allowance when management believes the uncollectibility of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. Accrued interest receivable on available-for-sale debt securities is excluded from the estimate of credit losses.

Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at amortized cost or principal balance outstanding. Amortized cost is the principal balance outstanding, net of purchase premiums and discounts and deferred loan fees and costs. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments.

Mortgage loans that are 180 days past due and commercial loans are charged off to the extent principal or interest is deemed uncollectible. Consumer and credit card loans continue to accrue interest until they are charged off no later than 120 days past due unless the loan is in the process of collection. Past-due status is based on the contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged off at an earlier date if collection of principal or interest is considered doubtful.

All interest accrued but not received for loans placed on nonaccrual is reversed against interest income. Interest received on such loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual. Under the cost-recovery method, interest income is not recognized until the loan balance is reduced to zero. Under the cash-basis method, interest income is recorded when the payment is received in cash. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and when, in the opinion of management, the loans are estimated to be fully collectible as to both principal and interest.

The Company has purchased loans, some of which have experienced more than insignificant credit deterioration since origination. Loans that meet at least one of the following criteria are considered to have experienced more-than-insignificant credit deterioration since origination at the date of acquisition: 1) delinquent as of the acquisition date; 2) has been downgraded since origination; 3) has been placed on nonaccrual status at any point since origination; or 4) for which credit spreads have widened beyond market-level thresholds. PCD loans are recorded at the amount paid for the loan. An allowance for credit losses is determined using the same methodology as other loans held for investment. The initial allowance for credit losses determined on a collective basis is allocated to individual loans. The sum of the loan’s purchase price and allowance for credit losses becomes its initial amortized cost basis. The difference between the initial amortized cost basis and the par value of the loan is a noncredit discount or premium, which is amortized into interest income over the life of the loan. Subsequent changes to the allowance for credit losses are recorded through provision expense.

The allowance for credit losses is a valuation account that is deducted from the loans’ amortized cost basis to present the net amount expected to be collected on the loans. Loans are charged off against the allowance when management believes the uncollectibility of a loan balance is confirmed. When forecasting expected recoveries, the amounts should not exceed the aggregate of amounts that have previously been or are expected to be charged-off loans. The Company has elected to not forecast recoveries.

Adjustments to historical loss information are made for differences in current loan-specific risk characteristics such as differences in underwriting standards, portfolio mix, delinquency level, or term as well as for changes in environmental and economic conditions, such as changes in unemployment rates, property values, or other relevant factors.

The Company applies Probability of Default (PD), and Loss Given Default (LGD), methodologies for all portfolio segments. The Company uses a Transition Matrix (TM) for PD components of the methodology and a historical average for the LGD components of methodology. The PD and LGD is applied to the current principal balance as of the reporting date. The TM determines the PD by tracking the historical movement of loans between loan risk tiers over a defined period of time. The Company currently has 16 portfolio segments for which we track monthly movement between either risk ratings or delinquency bands.

While the TM functions similarly across all portfolio segments, generally speaking, commercial portfolios use the Company’s risk rating scale and consumer portfolios use the delinquency day count, or delinquency band. Loans using risk ratings are scored utilizing the Company’s risk rating scale. The risk rating scale is 1-10, with 1 being the best rating, 6 being a pass but on watch, and 7-10 being various stages of criticized loans. Risk ratings 8 or greater and in a non-accrual status are considered in a defaulted state. Loans using delinquency band are measured using a 5-grade band, with 1 being current and 5 being 90 or more days past due.

The Company segments the loan portfolio into pools based on the following risk characteristics: financial asset type, collateral type, loan characteristics, credit characteristics, outstanding loan balances, contractual terms and prepayment assumptions, vintage, industry of borrower and concentrations, and historical or expected credit loss.

Commercial real estate non-owner-occupied loans. These loans include a mix of variable and fixed rate non-farm, non-residential real estate loans secured by non-owner-occupied properties. Commercial real estate non-owner-occupied loans are generally secured by first liens on income-producing real estate and generally mature in less than 10 years.

Construction land acquisition and development loans. Construction land acquisition and development loans are primarily to commercial builders for residential lot development and the construction of single-family residences and commercial real estate properties. Construction loans are generally underwritten pursuant to pre-approved permanent financing. During the construction phase the borrower pays interest only. Construction land acquisition and development loans generally mature in three years or less.

Residential construction loans. Residential construction loans are primarily to commercial builders or owner occupants for the construction of single-family residences. Construction loans are generally underwritten pursuant to credit worthiness or pre-qualification for permanent financing. During the construction phase the borrower pays interest only. Residential construction loans generally mature in one to two years.

Commercial construction loans. Commercial construction loans are primarily to commercial builders for commercial real estate properties. Construction loans are generally underwritten pursuant to credit worthiness or pre-qualification for permanent financing. During the construction phase the borrower pays interest only. Commercial construction loans generally mature in two years or less.

Agricultural real estate loans. These include loans secured by farmland or ranchland consisting of short, intermediate, and long-term structures to experienced agriculturalists who have demonstrated management capabilities, established production and historical financial performance. Agricultural real estate loans generally mature in ten years or less.

Commercial and floor plan loans. The Company provides a mix of variable and fixed rate commercial loans in addition to loans to finance dealership floor inventories. The loans are typically made to small and medium-sized manufacturing, wholesale, retail, and service businesses for working capital needs and business expansions. Commercial loans generally include lines of credit, business credit cards, and loans with maturities of five years or less and outstanding balances tend to be cyclical in nature. The loans are generally made with business operations as the primary source of repayment, and are typically collateralized by inventory, accounts receivable, equipment, and/or personal guarantees. Commercial and floor plan loans generally mature in seven years or less.

Agricultural loans. Agricultural loans generally consist of short and medium-term loans and lines of credit that are primarily used for crops, livestock, equipment, and general operations. Agricultural loans are ordinarily secured by assets such as livestock or equipment and are repaid from the operations of the farm or ranch. Agricultural loans generally have maturities of seven years or less, with operating lines for one production season.

Consumer indirect loans. These include loan contracts advanced for the purchase of automobiles, boats, and other consumer goods from the consumer product dealer networks within the market areas we serve. Indirect dealer loans are generally secured by automobiles, recreational vehicles, boats, and other types of personal property and are made on an installment basis. Consumer indirect line loans generally mature in seven years or less.

Consumer direct and advance line loans. These loans are originated for a variety of purposes including the purchase of automobiles, boats and other consumer goods, home improvements, medical expenses, vehicle repairs, debt consolidation, and planned expenses. Consumer direct and advance line loans generally mature in seven years or less.

Consumer credit card loans. These are lines of credit offered to clients in our market areas that are generally floating rate loans and include both unsecured and secured lines. Consumer credit card loans generally do not have stated maturities but are reviewed periodically and are unconditionally cancellable.

Residential 1-4 family and multi-family lending. These are loans to finance the purchase or refinance of residential property which are typically secured by first liens, inclusive of 1-4 family as well as 5+ residential properties. Residential 1-4 family loans generally mature within 15 years but can be up to 30 years. Multi-family loans generally mature in 10 years or less.

Commercial real estate multi-family loans. Commercial real estate multi-family loans are generally secured by first liens on income-producing rental real estate consisting of 5 or more residential dwelling units and generally mature in less than 10 years. For CECL related segmentation, multi-family loans are modeled with residential 1-4 family but are reported under Commercial Real Estate.

Commercial credit card loans. These are lines of credit for commercial purposes that are generally floating rate loans and include both unsecured and secured lines. For CECL related segmentation, commercial credit card loans are modeled separately but are reported under Commercial. Commercial credit card loans generally do not have stated maturities but are reviewed periodically and are unconditionally cancellable.

Agricultural credit card loans. Lines of credit for agricultural purposes that are generally floating rate loans and are unsecured or secured. For CECL related segmentation, agricultural credit card loans are modeled separately but are reported under Commercial. Agricultural credit card loans generally do not have stated maturities but are reviewed periodically and are unconditionally cancellable.

Expected credit losses are estimated over the contractual term of the loans, adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications unless either management has a reasonable expectation at the reporting date that a troubled debt restructuring will be executed with an individual borrower or the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancellable by the Company.

A loan for which the terms have been modified resulting in a concession, and for which the borrower is experiencing financial difficulties, is considered to be a troubled debt restructurings. The allowance for credit loss on a troubled debt restructuring is measured using the same method as all other loans held for investment, except when the value of a concession cannot be measured using a method other than the discounted cash flow method. When the value of a concession is measured using the discounted cash flow method, the allowance for credit loss is determined by discounting the expected future cash flows at the original interest rate of the loan.

The Company estimates expected credit losses over the contractual period in which the Company is exposed to credit risk via a contractual obligation to extend credit unless that obligation is unconditionally cancellable by the Company. Management considers our unused credit card lines and federal fund lines, extended to others, to be considered unconditionally cancellable. Credit card receivables are run through the transition matrices and their unused lines are excluded from the final loss calculation because they are unconditionally cancellable. The allowance for credit losses on off-balance sheet credit exposures is adjusted as a provision for credit loss expense. The estimate considers the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over the estimated life.