The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, disclosures of contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates are primarily used in our revenue recognition of construction in progress, fair value assumptions in accounting for business combinations and analyzing goodwill, investments, intangible assets and long-lived asset impairments and adjustments, allowance for doubtful accounts receivable, stock-based compensation, reserves for legal matters, realizability of deferred tax assets, unrecognized tax benefits and self-insured claims liabilities and related reserves.

Inventories consist of raw materials, work in process, finished goods, and parts and supplies held for use in the ordinary course of business. Inventory is valued at the lower of cost or net realizable value generally using the historical average cost or first-in, first-out (FIFO) method. When circumstances dictate, we write down inventory to its estimated net realizable value based on assumptions about future demand, market conditions, plans for disposal, and physical condition of the product. Where shipping and handling costs on inventory purchases are borne by us, these charges are included in inventory and charged to cost of services upon use in our projects or the providing of services.

Expenditures for repairs and maintenance are charged to expense when incurred. Expenditures for major renewals and betterments, which extend the useful lives of existing property and equipment, are capitalized and depreciated. Upon retirement or disposition of property and equipment, the capitalized cost and related accumulated depreciation are removed from the accounts and any resulting gain or loss is recognized in the statements of comprehensive income in the caption (gain) loss on sale of assets.

Goodwill attributable to each reporting unit is tested for impairment either by comparing the fair value of each reporting unit with its carrying value or by a qualitative assessment. These impairment tests are required to be performed at least annually. On an ongoing basis (absent any impairment indicators), we perform an impairment test annually using a measurement date of September 30. In evaluating goodwill for impairment, we have the option to first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is greater than its carrying value. If we determine that it is more likely than not that the carrying value of a reporting unit is greater than its fair value, then we perform an impairment test by calculating the fair value of the reporting unit and comparing this calculated fair value with the carrying value of the reporting unit.

We estimate the fair value of the reporting unit based on both a market approach and an income approach, using discounted estimated future cash flows. The market approach uses market multiples of enterprise value to earnings before interest, taxes, depreciation and amortization for comparable publicly traded companies. The income approach relies on significant estimates for future cash flows, projected long-term growth rates, and the weighted average cost of capital.

Debt issuance costs are included as a reduction of our debt outstanding, or alternately classified within other non-current assets if we have no borrowings drawn on our credit facility at the balance sheet date, and are amortized to interest expense over the scheduled maturity of the debt. Amortization expense of debt issuance costs was $152, $318 and $288, respectively, for the years ended 2020, 2019 and 2018. Remaining unamortized capitalized debt issuance costs were $736 and $782 at September 30, 2020, and 2019, respectively.

Revenue is generally recognized from a contract with a customer when: (i) it has approval and commitment from both parties, (ii) the rights of the parties are identified, (iii) payment terms are identified, (iv) the contract has commercial substance, and (v) collectability of consideration is probable. We consider the start of a project to be when the above criteria have been met and we have written authorization from the customer to proceed.

We recognize revenue on project contracts using the percentage of completion method. Project contracts generally provide that customers accept completion of progress to date and compensate us for services rendered measured in terms of units installed, hours expended or some other measure of progress. We recognize revenue on both signed contracts and change orders. A discussion of our treatment of claims and unapproved change orders is described later in this section. Percentage of completion for construction contracts is measured principally by the percentage of costs incurred and accrued to date for each contract to the estimated total cost for each contract at completion. We generally consider contracts to be substantially complete upon departure from the work site and acceptance by the customer. Contract costs include all direct material, labor and insurance costs and those indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and depreciation costs. Changes in job performance, job

conditions, estimated contract costs and profitability and final contract settlements can result in change orders under which the customer agrees to pay additional contract price. Revisions can also result in claims we might make against the customer to recover additional costs that have not been resolved through change orders with the customer. Except in certain circumstances, we do not recognize revenue or margin based on change orders or claims until they have been agreed upon with the customer. The amount of revenue associated with unapproved change orders and claims was immaterial for the years ended September 30, 2020, 2019 and 2018. Provisions for total estimated losses on uncompleted contracts are made in the period in which such losses are determined. The balances billed but not paid by customers pursuant to retainage provisions in project contracts are typically due upon completion of the contracts and acceptance by the customer. Based on our experience, the retention balance at each balance sheet date will be collected within the subsequent fiscal year.

Certain divisions in the Residential and Infrastructure Solutions segments use the completed contract method of accounting because the duration of their contracts is short in nature. We recognize revenue on completed contracts when the project is complete and billable to the customer. Provisions for estimated losses on these contracts are recorded in the period such losses are determined.

We record accounts receivable for all amounts billed and not collected. Generally, we do not charge interest on outstanding accounts receivable; however, from time to time we may believe it necessary to charge interest on a case by case basis. Additionally, we provide an allowance for doubtful accounts for specific accounts receivable where collection is considered doubtful as well as for general unknown collection issues based on historical trends. Accounts receivable not determined to be collectible are written off as deemed necessary in the period such determination is made. As is common in our industry, some of these receivables are in litigation or require us to exercise our contractual lien rights in order to collect. Our allowance for doubtful accounts at September 30, 2020 and 2019 was $2,613 and $1,184, respectively. We believe that our allowance for doubtful accounts is sufficient to cover uncollectible receivables as of September 30, 2020.

We regularly evaluate valuation allowances established for deferred tax assets for which future realization is uncertain. We perform this evaluation on a quarterly basis. The estimation of required valuation allowances includes estimates of future taxable income. In assessing the realizability of deferred tax assets, we must consider whether it is more likely than not some portion, or all, of the deferred tax assets will not be realized. We consider all available evidence, both positive and negative, in determining whether a valuation allowance is required. At September 30, 2020, we concluded, based upon the assessment of positive and negative evidence, that it is more likely than not that the Company will generate sufficient taxable income within the applicable net operating loss ("NOL") carryforward periods to realize its net deferred tax assets of $33,803. We considered the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. If actual future taxable income is different from these estimates, our results could be affected.

We retain the risk for workers’ compensation, employer’s liability, automobile liability, construction defects, general liability and employee group health claims, as well as pollution coverage, resulting from uninsured deductibles per accident or occurrence which are generally subject to annual aggregate limits. Our general liability program provides coverage for bodily injury and property damage. In many cases, we insure third parties, including general contractors, as additional insureds under our insurance policies. Losses are accrued based upon our known claims incurred and an estimate of claims incurred but not reported. Each year, we compile our historical data pertaining to the insurance experiences and actuarially develop the ultimate loss associated with our insurance programs other than pollution coverage for our Infrastructure Solutions segment. We believe that the actuarial valuation provides the best estimate of the ultimate losses to be expected under these programs.

We elect to discount the ultimate losses above to present value using an approximate risk-free rate over the average life of our insurance claims. For the years ended September 30, 2020 and 2019, the discount rate used was 0.3 percent and 1.6 percent, respectively. The present value of all insurance reserves for the workers’ compensation, auto and general liability recorded at September 30, 2020, and 2019 was $3,832 and $4,702, respectively. Our undiscounted reserves for employee group health claims at September 30, 2020, and 2019 were $2,422 and $1,981, respectively, and are anticipated to be resolved within the year ended September 30, 2021.

We evaluate the recoverability of property and equipment and other long-lived assets as facts and circumstances indicate that any of those assets might be impaired. If an evaluation is required for our assets we plan to hold and use, the estimated future undiscounted cash flows associated with the asset are compared to the asset’s carrying amount to determine if an impairment of such property has occurred. The effect of any impairment would be to expense the difference between the fair value of such property and its carrying value. Estimated fair values are determined based on expected future cash flows discounted at a rate we believe incorporates the time value of money, the expectations about future cash flows and an appropriate risk premium.

Financial instruments, which potentially subject us to concentrations of credit risk, consist principally of cash deposits and accounts receivable. Through delayed payment terms, we at times grant credit, usually without collateral, to our customers, who are generally large public companies, contractors and homebuilders throughout the United States. Consequently, we are subject to potential credit risk related to changes in business and economic factors throughout the United States, specifically, within the construction, homebuilding and mission critical facility markets. However, we are entitled to payment for work performed and generally have certain lien rights in that work. Further, management believes that its contract acceptance, billing and collection policies are adequate to manage potential credit risk. We routinely maintain cash balances in financial institutions in excess of federally insured limits. We periodically assess the financial condition of these institutions where these funds are held and believe the credit risk is minimal. We maintain the majority of our cash and cash equivalents in money market mutual funds. There can be no assurance, however, that we will not be adversely affected by credit risks we face.

We measure and record compensation expense for all share-based payment awards based on the fair value of the awards granted at the date of grant. The fair value of restricted stock awards and phantom stock unit awards is determined based on the number of shares granted and the closing price of IES’s common stock on the date of grant. For awards vesting upon achievement of a market condition, the likelihood of achieving that market condition is considered in determining the fair value of the grant, which we expense ratably over the vesting period. For awards vesting upon achievement of a performance condition, we record expense based on the grant date fair value when it becomes probable the performance condition will be achieved. Forfeitures are recorded in the period in which they occur. The resulting compensation expense is recognized on a straight-line basis over the requisite service period, which is generally the vesting period.

The Company maintains a rabbi trust to fund certain deferred compensation plans. The securities held by the trust are classified as trading securities. The investments are recorded at fair value and are classified as other non-current assets in the accompanying Consolidated Balance Sheets as of September 30, 2020, and 2019. The changes in fair values are recorded as a component of other income (expense) in the Consolidated Statements of Comprehensive Income (Loss).

In connection with our acquisitions of STR Mechanical, LLC (“STR Mechanical”) in fiscal 2016 and NEXT Electric, LLC (“NEXT Electric”) in fiscal 2017, we acquired 80 percent interests in these entities, and the remaining 20 percent was retained by the third party sellers. The interests retained by those third party sellers are identified on our Consolidated Balance Sheets as noncontrolling interest, classified outside of permanent equity. Under the terms of the operating agreements governing these entities, after five years from the dates of the acquisitions, we may elect to purchase, or the third party sellers may require us to purchase, part or all of the remaining 20 percent interests in these entities. The purchase price is variable, based on a multiple of earnings as defined in the operating agreements. Therefore, this noncontrolling interest is carried at the greater of the balance determined under Accounting Standards Codification Topic 810 ("ASC 810") and the redemption amounts assuming the noncontrolling interests were redeemable at the balance sheet date. If all of these interests had been redeemable at September 30, 2020, the redemption amount would have been $1,582. For the year ended September 30, 2020, we recorded a decrease to retained earnings of $194 to increase the carrying amount of noncontrolling interest in NEXT Electric to its redemption amount had it been redeemable at September 30, 2020. For the year ended September 30, 2018, we recorded an increase to retained earnings of $44 to offset an increase to noncontrolling interest recorded in fiscal 2017, decreasing the carrying amount of the noncontrolling interest in STR to the balance determined under ASC 810, as if it had been redeemable at September 30, 2018, as the redemption amount would have been less than the carrying amount.

We enter into various contractual arrangements for the right to use facilities, vehicles and equipment. We evaluate whether each of these arrangements contains a lease and classify all identified leases as either operating or finance. If the arrangement is subsequently modified, we re-evaluate our classification. The lease term generally ranges from two to ten years for facilities and three to five years for vehicles and equipment. Our lease terms may include the exercise of renewal or termination options when it is reasonably certain these options will be exercised. Our lease agreements do not contain any material residual value guarantees or restrictive covenants.

Upon commencement of the lease, we recognize a lease liability and corresponding right-of use ("ROU") asset for all leases with an initial term greater than twelve months. Lease liabilities represent the present value of our future lease payments over the expected lease term. As most of our leases do not provide an implicit rate, we generally use our incremental borrowing rate as the discount rate in calculating the present value of the lease payments. The incremental borrowing rate is determined by identifying a synthetic credit rating for the consolidated company, where treasury functions are centrally managed, and adjusting the interest rates from associated indexes for differences in credit risk and interest rate risk. We have elected to combine the lease and nonlease components in the recognition of our lease liabilities across all classes of underlying assets. ROU assets represent our right to control the use of the leased asset during the lease and are recognized in an amount equal to the lease liability with adjustments for prepaid or accrued rent, lease incentives or unamortized initial direct costs. Costs associated with operating lease assets are recognized on a straight-line basis over the term of the lease. Our lease assets are tested for impairment in the same manner as long-lived assets used in operations.

Certain lease contracts include obligations to pay for other services, such as operations and maintenance. Where the costs of these services can be identified as fixed or fixed-in-substance, the costs are included as part of the future lease payments. If the cost is not fixed at the inception of the lease, the cost is recorded as a variable cost in the period incurred.

In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update No. 2016-13, Financial Instruments – Credit Losses (“ASU 2016-13”), which requires companies to consider historical experiences, current market conditions and reasonable and supportable forecasts in the measurement of expected credit losses, with further clarifications made in April 2019 and May 2019 with the issuances of Accounting Standard Updates No. 2019-04 and 2019-05. This update is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, although early adoption is permitted. We plan to adopt this standard on October 1, 2020, and do not expect the adoption to have a material effect on our Consolidated Financial Statements.

In August 2018, the FASB issued Accounting Standard Update No. 2018-13, Fair Value Measurement Disclosure Framework (“ASU 2018-13”), to modify certain disclosure requirements for fair value measurements. Under the new guidance, registrants will need to disclose weighted average information for significant unobservable inputs for all Level 3 fair value measurements. The guidance does not specify how entities should calculate the weighted average, but requires them to explain their calculation. The new guidance also requires disclosing the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements of instruments held at the end of the reporting period. This guidance is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, although early adoption is permitted for either the entire standard or only the provisions that eliminate or modify the requirements. We plan to adopt this standard on October 1, 2020, and do not expect the adoption to have a material effect on our Consolidated Financial Statements.

In February 2016, the FASB issued Accounting Standard Update No. 2016-02, Leases (“ASU 2016-02”). Under ASU 2016-02, lessees need to recognize a ROU asset and a lease liability on their balance sheets for all leases, other than those that meet the definition of a short-term lease. For income statement purposes, leases must be classified as either operating or finance. Operating leases result in straight-line expense, while finance leases are accounted for similar to capital leases under the previous lease accounting standard. We adopted ASU 2016-02 on October 1, 2019 using a modified retrospective transition approach. Using the optional transition method allowed under Accounting Standard Update No. 2018-11, prior period amounts were not adjusted retrospectively and continue to be reported using the previous accounting standards in effect for the period presented. We elected to utilize all of the available practical expedients with the exception of the practical expedient permitting the use of hindsight when determining the lease term and assessing impairment of ROU assets. Therefore, we did not reassess whether any of our existing or expired contracts contained leases or the classification of or initial direct costs included in our existing or expired leases.

The adoption of ASU 2016-02 resulted in the recognition of ROU assets of approximately $32,434 and operating lease liabilities of approximately $32,237 on our Consolidated Balance Sheets at the adoption date. The difference between the ROU assets and lease liabilities was primarily due to previously accrued rent expense relating to periods prior to October 1, 2019. The adoption did not have a significant impact on our Consolidated Statements of Comprehensive Income or Cash Flows. See Note 9, “Leases” for additional discussion of our lease accounting policies and expanded disclosures.

In June 2018, the FASB issued Accounting Standard Update No. 2018-07, Compensation—Stock Compensation (“ASU 2018-07”), to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments for employees, with certain exceptions. Under the new guidance, the cost for nonemployee awards may be lower and less volatile than under current GAAP because the measurement generally will occur earlier and will be fixed at the grant date. This update was adopted as of October 1, 2019 with no impact to our financial statements.