A large cost segregation refund goes to the Joint Committee on Taxation (JCT) only when it falls within a reportable category. A refund shown on an original return as filed does not qualify under IRC §6405(a), even if estimated tax payments make the refund larger than $2 million or $5 million for a C corporation. The principal reportable categories are refund claims made on amended returns, tentative carryback allowances, and examination-determined overassessments. The IRS explains which large refunds and credits are subject to JCT review.

For real estate investors, the most likely cost segregation path is an amended-return refund claim after a depreciation correction, not a §481(a) deduction claimed on a timely filed original return. A covered refund claim is generally examined, or assigned and then surveyed, before the IRS prepares its Joint Committee report. Taxpayers should therefore expect possible IRS exam contact on the claim itself; the later JCT staff review is the separate congressional oversight step, not another audit.

Understanding the review before you file gives you and your CPA an advantage. You can prepare documentation, reconcile your numbers, and avoid delays. This article explains what the review is, when a cost segregation refund triggers it, what happens at each stage, and how to prepare.

What Is the Joint Committee on Taxation?

The JCT is a nonpartisan committee of the United States Congress. It draws its members from the Senate Finance Committee and the House Ways and Means Committee. Its professional staff of attorneys, accountants, and economists reviews tax legislation and examines large refund cases.

Under Internal Revenue Code Section 6405, the IRS generally cannot pay a covered refund claim or examination overassessment until 30 days after it submits a report on the case to the JCT. Tentative carryback allowances under §6405(b), including Forms 1045 and 1139, follow the opposite sequence: the IRS pays the allowance first and reports it afterward. In every category, the rule applies only when the refund is more than the threshold, not equal to it.

Current thresholds:

• $2 million for individuals, estates, and trusts. Partnerships and S corporations generally do not receive income tax refunds themselves, so the threshold is usually tested at the partner or shareholder level; BBA partnership adjustments are a limited exception.
• $5 million for C corporations

The higher C-corporation threshold has applied since December 2014. Different categories of refund, such as an examination refund and a tentative carryback, are tested separately rather than added together.

This oversight is not new. Congress created the Joint Committee in the Revenue Act of 1926, and the Revenue Act of 1928 gave it authority to review large refunds, then any refund above $75,000. Since then, the threshold has risen in steps to today's figures.

The JCT does not approve or deny refunds. Its staff reviews the IRS's work and may ask questions or request more information. The statute does not require the IRS to follow the JCT's recommendations, so the role is advisory. In practice, the IRS does not release the refund until the review concludes. If the staff has no objection, the IRS issues the refund.

When Does a Cost Segregation Refund Trigger JCT Review?

The trigger is a covered refund claim, typically an amended return or carryback, not the size of a §481(a) deduction reported on an original return.

Three cost segregation paths can reach JCT review:

1. Amended-return refund claims. If only one return has been filed using an incorrect depreciation method, the taxpayer generally corrects it by amendment. A claim exceeding $2 million, or $5 million for a C corporation, can be reportable after examination or survey.
2. Tentative carryback allowances. A qualifying carryback under §6411 is paid first and reviewed under §6405(b) afterward. After the TCJA, this path is generally limited to categories that still permit carrybacks, such as certain farming losses.
3. Examination-determined overassessments. If an IRS examination determines that the taxpayer overpaid by more than the applicable threshold, the resulting overassessment can be reportable.

A Form 3115 look-back follows a different path. Once an impermissible depreciation method has appeared on two or more consecutive returns, the taxpayer generally files Form 3115 with a timely filed original return and claims the negative §481(a) adjustment in the year of change. Any refund shown on that original return as filed is excluded from §6405(a), regardless of size.

Consider an individual investor correcting the prior year after only one return was filed using straight-line depreciation. The investor's $30 million multifamily portfolio has a $24.6 million depreciable basis after an 18% land allocation. A study reclassifies $6 million, 20% of purchase price and about 24% of depreciable basis, into shorter recovery periods. Because the buildings were placed in service in years when bonus depreciation was 100%, the catch-up captures the full reclassified amount. The permanent 100% rate under current law applies separately to qualified property acquired and placed in service after January 19, 2025.

At the 37% top marginal rate that applies for 2026, the $6 million depreciation correction reduces tax by about $2.22 million ($6,000,000 × 37% = $2,220,000). Because the investor claims that amount on an amended return and it exceeds $2 million, the refund claim can be reported to the JCT before payment.

Does every large cost segregation study trigger a JCT review?

No. The review applies only to refunds above the threshold that also fall within a reportable category. The trigger is a refund claim, typically an amended return or a carryback, not a §481(a) deduction on an original return. A refund shown on the original return as filed does not go to the JCT under §6405(a), regardless of its size.

What Happens During the Review Process

Reaching this stage usually means the IRS has examined the refund claim, or assigned and surveyed it, and prepared its analysis. The taxpayer should expect possible exam contact on the claim itself. The JCT staff review is a separate congressional oversight step, not a second audit. Here is the sequence for a §6405(a) refund claim.

Step 1: The IRS completes the case. The examiner verifies the amended return or other refund claim, reviews the cost segregation study and depreciation correction, and calculates the allowable refund.

Step 2: The IRS prepares a Joint Committee report. The report summarizes the taxpayer, the basis for the refund, the study findings, and the examiner's conclusions. The IRS reviews it internally before sending it.

Step 3: The report goes to JCT staff. The IRS submits the report to the JCT's refund-review staff.

Step 4: JCT staff reviews the case. The staff examines the report and supporting documents. Three outcomes are possible:

• No objection. The staff accepts the IRS's findings, and the refund moves forward
• Request for information. The staff asks the IRS for more detail, which can extend the timeline
• Formal questions. In rare cases, the staff raises substantive concerns that send the IRS back to its analysis

Step 5: The IRS issues the refund. For a §6405(a) claim or examination overassessment, the IRS cannot release payment until at least 30 days after submitting the report. Tentative carryback allowances under §6405(b) are paid before the post-payment JCT review.

The JCT cannot independently deny a refund. Its role is advisory. But if the staff raises questions the IRS cannot answer, the IRS may reconsider its position.

How long does JCT review add to my refund?

For refund claims and examination overassessments, the statute prevents payment for at least 30 days after the IRS submits its report. In practice, the IRS may hold the refund until the review concludes, which can add a month or more beyond the examination and normal processing time. Tentative carrybacks are different because they are paid before the JCT report. Complete, well-documented cases move fastest; missing information, thin studies, or unusual claims take longer.

How to Prepare Your Cost Segregation Study for JCT Scrutiny

If your refund may exceed the JCT threshold, preparation begins before you file. These five steps strengthen your position.

Strategy 1: Use an engineering-based study. Desktop estimates and software-only reports do not hold up under JCT scrutiny. Specialists should examine the property through a site visit or virtual inspection. The IRS and JCT staff expect an engineering methodology, not a statistical estimate.

Strategy 2: Document the inspection thoroughly. Support every component with photos, floor plans, and property records. The report should reference specific building elements, not generic categories. If it lists "$85,000 in specialty electrical," the documentation should show exactly what was classified and why.

Strategy 3: Verify all financial calculations. Check every number. The purchase price, land value allocation, depreciable basis, reclassification amounts, bonus depreciation figures, and tax-savings totals must reconcile. A single math error can delay the review by weeks.

Strategy 4: Use the correct correction procedure. If only one return has been filed using the wrong depreciation method, generally amend that return; a refund claim above the threshold is the cost segregation scenario most likely to reach JCT review. Once two or more consecutive returns use the impermissible method, the automatic-consent procedure under Rev. Proc. 2015-13 and the current list in Rev. Proc. 2025-23 generally applies. Designated Change Number 7 covers a change from an impermissible to a permissible depreciation method. Attach Form 3115 to the timely filed original return for the year of change, including extensions, send the duplicate copy to Ogden, and deduct a negative §481(a) adjustment in full in that year.

Strategy 5: Maintain a complete paper trail. Keep your closing statement, renovation invoices, photos, floor plans, prior depreciation schedules, amended return or Form 3115, and the full cost segregation report organized and accessible. A refund claim must also fit within the §6511 limitations period, generally three years from filing the return or two years from paying the tax, subject to the statute's detailed rules, which limits how far back an amended claim can reach. If the IRS or JCT staff requests documents, you can respond quickly.

Strong preparation looks like this. An investor with a large commercial real estate portfolio files an amended-return refund claim, supported by a cost segregation study, for well above the $2 million threshold. The report includes detailed engineering analysis, 200-plus property photos, floor plans for every building, and a depreciation schedule that reconciles to the tax return. The review clears in about six weeks with no follow-up requests, and the IRS releases the refund in full.

What the JCT Staff Is Looking For

The staff evaluates the quality of the IRS examiner's work and the supporting documentation. Its focus areas include:

• Engineering methodology. Does the study follow accepted cost segregation practices? Is each classification supported by inspection and IRS guidelines?
• Depreciation accuracy. Are the asset recovery periods applied correctly? Is bonus depreciation calculated properly under current law?
• Depreciation correction. Does the amended-return adjustment, or any §481(a) catch-up where applicable, accurately account for depreciation already claimed and the bonus rate from the property's original acquisition and placed-in-service year?
• Consistency. Do the numbers in the study match the amended figures, the tax return, and any Form 3115 or supporting schedules?
• Documentation completeness. Is the study backed by photos, floor plans, closing statements, and renovation records?

In practice, several patterns tend to draw extra questions:

• Round-number reclassification amounts, which can suggest estimates rather than engineering analysis
• Desktop-only studies with no site visit or virtual inspection documentation
• Using the wrong correction procedure, or filing an incomplete amended return or Form 3115
• Unusually high reclassification percentages without supporting detail
• Inconsistencies between the study and the tax return

Common Mistakes That Delay JCT Approval

Every mistake adds time. Here are the five most common.

Mistake 1: Using the wrong correction procedure. Amending after the method is adopted, filing Form 3115 when only one return needs correction, or omitting required schedules and calculations can send the case back to the examiner and add weeks.

Mistake 2: Thin engineering reports. A report that lists asset categories without supporting detail raises questions. The staff expects to see how each classification was determined.

Mistake 3: Math errors in depreciation schedules. If the reclassified amounts do not reconcile to the depreciable basis, or the tax-savings figures are inconsistent, the staff will flag it.

Mistake 4: Missing supporting documentation. "We will provide that later" is not a plan. If you cannot produce your closing statement or renovation records promptly, the delay falls on you.

Mistake 5: Inconsistency between study and return. When the report says one thing and the return says another, the staff must resolve the gap. A simple reconciliation before filing avoids this.

Each of these can add weeks to the review, keeping your refund tied up until the questions are resolved.

Key Takeaways

• JCT reporting applies only to refunds above $2 million, or $5 million for C corporations, that fall within a covered category such as an amended-return claim, tentative carryback, or examination overassessment.
• The cost segregation trigger is typically a refund claim on an amended return, often the one-return correction case, not a §481(a) deduction reported on an original return.
• Once two or more consecutive returns use the wrong depreciation method, Form 3115 generally belongs on the timely filed original return for the year of change; a refund shown on that original return is excluded from §6405(a).
• Covered refund claims are generally examined or surveyed before the IRS prepares its report. The JCT staff review is congressional oversight, not a second audit.
• The 30-day prepayment period applies to refund claims and examination overassessments. Tentative carryback allowances are paid first and reported afterward.
• Common delays include the wrong correction procedure, thin reports, math errors, missing documents, and inconsistencies between the study, amended claim, and tax schedules.

The review process rewards preparation. Investors who file with complete, engineering-based studies and clean documentation move through it smoothly.

Wondering whether your next refund could land in front of the Joint Committee? Book a call to see how a fully documented study clears review without delay.

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