Form 8697 for Long-Term Contracts: Filing and Interest Computation

Form 8697 instructions apply in any year you complete a long-term contract that you reported under the percentage-of-completion method (or the percentage-of-completion capitalized cost method). You file the form with that year’s return to compute look-back interest: interest on the difference between the tax you paid each year using estimated contract figures and the tax you would have paid using the final actual figures. The form does not change your total tax across the life of the contract. It only settles the time value of money on amounts that were temporarily over- or underpaid.

When You Have to File Form 8697

You file Form 8697 for each tax year in which you complete a long-term contract entered into after February 28, 1986, that you accounted for using PCM or the percentage-of-completion capitalized cost method. The computation runs separately for each contract. Complete three contracts in one year, and you perform three independent look-back calculations on the same form.¹

Partnerships and S-corporations apply the look-back method at the entity level. The entity files Form 8697 with Form 1065 or Form 1120-S, pays or receives the net interest itself, and notifies each partner or shareholder of their share. Individual owners do not file their own Form 8697 for these contracts.

Contracts That Are Exempt

Three situations pull a completed contract out of the look-back requirement for regular tax:

Small contracts. The method does not apply to a contract whose final gross price does not exceed the lesser of $1,000,000 or 1 percent of your average annual gross receipts for the three tax years before the year the contract was completed, provided the contract was also completed within two years of its start date. Both conditions must be met.²
Home construction contracts. If 80 percent or more of estimated total costs relate to building or improving dwelling units in buildings with four or fewer units, the contract is exempt from PCM entirely, so no look-back calculation is needed for regular tax.
The de minimis election. You can elect to skip the look-back method if your cumulative taxable income under the contract for each prior year was within 10 percent of the look-back income figure. The election applies to all long-term contracts completed during the election year and every year after, unless the IRS approves a revocation.³

One boundary to know before you decide you’re done. If a non-home construction contract is exempt from PCM only because you qualify as a small contractor, you must still use PCM to compute alternative minimum taxable income and apply the look-back method to that AMT income.¹ Home construction contracts are outside that AMT requirement.

Choose Your Method Before You Start

The form offers two calculation paths, and the choice controls how much work follows.

The Regular Method (Part I) recomputes your actual tax liability for each prior year, substituting the final contract figures for the original estimates. You need complete tax data for every affected year, including the marginal rates that applied. On a five-year contract, that’s five recomputed returns.

The Simplified Marginal Impact Method (SMIM, Part II) skips the recomputation. It applies a flat assumed rate to the income adjustment: the highest statutory rate in effect for each prior year under Section 1 for individuals or Section 11 for corporations. No year-by-year tax return reconstruction.¹

To elect the SMIM, attach a statement to your timely filed return (including extensions) for the first year you want it to apply, indicating that you are electing the simplified method under Regulations section 1.460-6(d). The election sticks for all future contracts unless the IRS consents to a revocation. Pass-through entities that apply the look-back method at the entity level are required to use the SMIM.¹

What to Gather Before You Open the Form

The calculation is only as good as the records behind it. Pull everything before you start.

Final contract figures: the actual total contract price and actual total costs at completion. These replace the estimates.
Year-by-year income allocations: the income and deductions you reported under the contract for each prior tax year, from the original returns or any amended versions.
Prior-year tax returns. Under the Regular Method you need enough detail to recompute the tax liability for each affected year, including applicable credits. Under the SMIM you need only the income adjustments and the highest statutory rate for each year.
IRS quarterly interest rates for the underpayment and overpayment amounts, covering every quarter from the due date of each prior year’s return through the filing date of the current return.⁴

Working Through Part I Line by Line

Part I uses one column per prior year in which you reported income from the contract. The lines within each column work as follows.

Line 1. Your taxable income (or loss) for the prior year as originally reported or previously adjusted. Do not reduce this by net operating loss or capital loss carrybacks unless those carrybacks are required to properly compute look-back interest under Section 460.¹

Line 2. The income adjustment. This is the difference between the contract income you actually reported (based on estimates) and the income you should have reported (based on final actual figures). A net increase is positive; a net decrease is negative. Account for other income and expense changes that flow from the contract adjustment.⁵

Line 3. Add Lines 1 and 2 to get adjusted taxable income for look-back purposes. A negative result is a look-back net operating loss created or changed by the contract adjustment.

Line 4. The hypothetical tax on the Line 3 amount, using the tax rates actually in effect for that prior year. Reduce by allowable credits (other than refundable credits), but do not factor in credit carrybacks. Include any AMT that would have applied.¹

Line 5. The tax liability you actually reported (or that was previously adjusted) for that prior year, computed on the same basis as Line 4.

Line 6. Line 4 minus Line 5. Positive means you underpaid that year and owe the IRS interest. Negative means you overpaid and the IRS owes you interest.⁵

Repeat for every prior year the contract spanned. The Line 6 amounts are the principal on which look-back interest is computed.

Computing the Interest

Each prior year’s Line 6 amount generates its own interest stream. The accrual period runs from the due date of that prior year’s return (ignoring extensions) through the earlier of the due date of the current return or the date you actually file the current return and pay any tax due.¹ A contract that spanned five prior years produces five separate interest calculations, each starting from a different date.

Interest compounds daily, and the applicable rate changes every quarter. Apply the IRS underpayment rate to tax increases and the overpayment rate to tax decreases. Corporate overpayments above $10,000 use a lower rate (the federal short-term rate plus 0.5 percentage points).⁴

Net the total interest owed against the total interest refundable across all prior years. That single net figure is the only financial output of the form.

Filing the Form and Reporting the Result

Attach Form 8697 to your tax return for the completion year. It must be filed by the due date of that return, including valid extensions.¹

Where the net interest lands depends on the filer:

Individuals filing Form 1040. If you owe interest, include it in your total tax and write “From Form 8697” and the amount on the line next to the total tax entry.¹
C-corporations. Report interest due on the schedule used to calculate total tax liability.
Partnerships and S-corporations. The entity files Form 8697 with its own return and pays or receives the interest at the entity level. Partners and shareholders receive notice of their share but do not file separate Forms 8697.

If the calculation yields a refund, the interest the IRS pays you is taxable interest income in the year received or accrued.⁶ Estimated tax penalties do not apply to look-back interest amounts, but failure to pay interest you owe can trigger the standard underpayment penalty under Section 6651.³

Deductibility of the Interest You Pay

Treatment depends on the type of taxpayer. C-corporations (other than S-corporations) can deduct look-back interest they pay as an interest expense in the year paid or incurred. Individuals and other taxpayers cannot deduct look-back interest at all.¹ Look-back interest received from the IRS is taxable interest income for all taxpayers regardless of entity type; it is not treated as a reduction in tax liability or a tax refund.⁶

If the Contract Changed Hands Mid-Stream

Ownership changes before completion do not simply pass the look-back to the new owner. The result depends on the type of transaction.

In a constructive completion transaction, the old taxpayer treats the contract as completed in the year of the transfer and applies the look-back method to all pre-transaction years. The new taxpayer is treated as entering a fresh contract and applies the look-back method to only the post-transaction years when the contract actually completes.¹

In a step-in-the-shoes transaction, the new taxpayer inherits the entire contract history. At completion, the new taxpayer applies the look-back method to both pre- and post-transaction years. Regulations sections 1.460-4(g) and 1.460-6(g) govern which category a particular transaction falls into.

Records to Hold Onto

You cannot complete Form 8697 without your year-by-year cost allocations, estimated contract prices, and prior-year returns for every year the contract was active. Because the look-back happens in the completion year, and the statute of limitations on that return does not start until you file it, the practical retention period stretches well past the usual three years after filing. Keep all contract-related records from the first year of the contract through at least three years after filing the return for the completion year.⁷

1
Internal Revenue Service. Instructions for Form 8697 – Interest Computation Under the Look-Back Method for Completed Long-Term Contracts
2
Office of the Law Revision Counsel. 26 US Code 460 – Special Rules for Long-Term Contracts – Section: (b)(3) Special Rules
3
Internal Revenue Service. Examination and Closing Procedures Form 8697, Look-Back Interest
4
Internal Revenue Service. Quarterly Interest Rates
5
Internal Revenue Service. Form 8697 – Interest Computation Under the Look-Back Method for Completed Long-Term Contracts
6
eCFR. 26 CFR 1.460-6 – Look-Back Method
7
Internal Revenue Service. How Long Should I Keep Records?