IRS Form 921-I – IRS Form 921-I is a specialized IRS consent form used by investors in certain pass-through entities to extend the statute of limitations for assessing income and profits tax deficiencies. Its full title is Consent Fixing Period of Limitation on Assessment of Income and Profits Tax (S-Corporations, Partnerships, Limited Liability Companies, Trusts, Syndicates, Pools, Etc.).
This form specifically supports real estate developers and investors applying the Alternative Cost Method (ACM) for estimated future common improvement costs in projects sold under contract. You can download the current official PDF directly from the IRS here: https://www.irs.gov/pub/irs-pdf/f921i.pdf (Rev. 4-2015, Catalog Number 31727W).
What Is IRS Form 921-I and Why Does It Exist?
Form 921-I allows the IRS and the taxpayer (an investor/shareholder/partner/member/beneficiary) to agree that the IRS may assess additional tax attributable to the use of the ACM for a specific real estate project up to one year after the return is filed for the tax year in which the project is expected to be completed.
Key features of the consent:
- It is project-specific and limited only to deficiencies from the alternative cost method for the described real estate project.
- It does not extend the statute for unrelated issues or deprive the taxpayer of appeal rights.
- If the IRS mails a notice of deficiency by the extended date, the period is further extended by the suspension period plus 60 days.
- A return filed early is treated as filed on the due date (without extensions) for purposes of this consent.
This form applies to non-TEFRA entities (those not subject to the old unified audit procedures under the Tax Equity and Fiscal Responsibility Act). TEFRA entities use Form 921-P instead, and entities under the Bipartisan Budget Act (BBA) centralized audit regime use Form 921-M.
Historical Context: Tied to Revenue Procedure 92-29
Form 921-I was required under Rev. Proc. 92-29 (1992-1 C.B. 748). This procedure let real estate developers include the allocable share of estimated future common improvement costs (e.g., roads, utilities, amenities) in the basis of units sold before the costs were actually incurred under the economic performance rules of IRC § 461(h).
To use this method on a per-project basis, developers and their investors had to:
- File detailed requests and annual statements.
- Execute statute extension consents via the Form 921 series.
The form extends the normal 3-year assessment period (IRC § 6501) specifically for ACM-related adjustments.
Major Update: Rev. Proc. 92-29 Superseded by Rev. Proc. 2023-9 (Effective for Years Beginning After Dec. 31, 2022)
In January 2023, the IRS issued Rev. Proc. 2023-9, which obsoletes Rev. Proc. 92-29 and modernizes the Alternative Cost Method into an optional safe-harbor method of accounting under IRC §§ 446 and 481.
Key changes under Rev. Proc. 2023-9:
- No per-project election or detailed annual disclosures required.
- Applies to all qualifying projects in a trade or business (not project-by-project).
- No statute of limitations extension required — Form 921-I (and related forms) is no longer needed for new ACM adoptions.
- Developers change to (or from) the new method by filing Form 3115 (Application for Change in Accounting Method), often automatically under Rev. Proc. 2023-24 or successors.
- Simplified rules, reduced administrative burden, and clearer application to § 460 long-term contracts.
Current status (as of 2026):
Form 921-I remains available on IRS.gov and may still apply to legacy projects elected under the old Rev. Proc. 92-29 where the project completion year extends into 2023 or later, or during transition via Form 3115. The IRS Internal Revenue Manual (IRM 25.6.22, revised August 2025) continues to reference the Form 921 series in the context of the former procedure. Always consult a tax professional to determine applicability to your situation.
How to Complete IRS Form 921-I (Step-by-Step)?
The two-page form is straightforward and is typically prepared or reviewed by the IRS but can be initiated by the taxpayer under the old procedure. Follow the instructions on page 2.
- Entity and Project Information (top of page 1):
- Entity name, type (S-Corp, Partnership, LLC, Trust, etc.), TIN, and address.
- Real Estate Project description (must be specific).
- Investor’s name and role (Shareholder, Partner, Member, Beneficiary, etc.).
- Consent Language (pre-printed):
- Tax years affected.
- Extension date: Up to 1 year after filing the return for the expected project completion year.
- Signature Section (bottom of page 1):
- Taxpayer name(s), signature(s), date.
- Spouse’s signature if joint return years are involved.
- Taxpayer’s representative (with power of attorney if not previously filed).
- Entity officer(s) name, title, signature, date (if investor is an entity).
- IRS official’s name, title, signature, and date (must be a delegated official per Delegation Order 25-2).
Signature rules (critical):
- Each investor must sign (or authorized representative).
- Joint returns require both spouses’ signatures (one may act as agent with POA).
- Fiduciaries attach Form 56 if not previously filed.
- No seal required unless mandated by entity governing documents.
- Fax/digital signatures are acceptable if properly documented (per IRM 25.6.22).
Return the original and one copy to the IRS for acceptance.
Related Forms in the 921 Series
| Form | Use Case | Entity Type |
|---|---|---|
| Form 921 | General consent to extend assessment period | Individuals, C-Corps, etc. |
| Form 921-I | ACM for non-TEFRA pass-through investors | S-Corps, Partnerships (non-TEFRA), LLCs, Trusts |
| Form 921-P | ACM for TEFRA partnerships/LLCs | TEFRA entities |
| Form 921-M | Partnership adjustments under BBA regime | Post-2017 BBA partnerships |
| Form 921-A | Older version (largely superseded) | Various |
Frequently Asked Questions
Is Form 921-I still required in 2026?
For new ACM use under Rev. Proc. 2023-9, no. It may still be relevant for legacy projects or transitions.
Where do I file it?
Return the signed original and copy to the IRS office handling the taxpayer’s account or as directed by the examining agent/territory manager.
Does it affect my appeal rights?
No — the form explicitly states it does not deprive taxpayers of any appeal rights.
Can I limit the extension?
Yes — it is already limited to the specific project and ACM adjustments.
Conclusion and Next Steps
IRS Form 921-I served as an important tool for real estate investors using the legacy Alternative Cost Method under Rev. Proc. 92-29. With the issuance of Rev. Proc. 2023-9, the process has been significantly simplified, eliminating the need for statute extensions in most new cases.
For the latest guidance:
- Download the form: IRS Form 921-I PDF
- Review Rev. Proc. 2023-9: Available on IRS.gov
- Check IRM 25.6.22 for consent procedures
Tax rules for real estate development are complex and fact-specific. This article is for informational purposes only and is not tax advice. Consult a qualified CPA or tax attorney familiar with real estate accounting methods and your specific projects to ensure compliance.
Last updated: February 2026. All information sourced directly from official IRS publications, forms, Revenue Procedures, and the Internal Revenue Manual.