IRS Partnership Audit Rules 2026: What Every Multi-Member LLC Owner Must Know

If you own a share of a multi-member LLC or partnership, there is a tax rule on the books since 2018 that most business owners still do not know about -- and the IRS is actively using it. The Bipartisan Budget Act centralized partnership audit regime, known as the BBA, fundamentally changed how the IRS audits partnerships. Under the old rules, auditing a partnership meant chasing down each partner individually. Under the BBA, the IRS can examine the partnership return, calculate a tax adjustment, and collect a check directly from the partnership entity -- at the highest possible tax rate -- without ever contacting you personally.

In 2026, despite significant IRS staffing changes, partnership audits remain one of the agency's active enforcement priorities. If your partnership has not reviewed its exposure to the BBA regime, now is the time.

What Changed: The Old Rules vs. the BBA Regime

Before 2018, partnerships were audited under TEFRA rules -- a process that required the IRS to open audit proceedings against every partner individually, amend each partner's personal return, and collect tax from each person separately. It was slow, expensive for the IRS, and most small adjustments were not worth the effort to pursue. As a result, partnerships were effectively under-audited for decades relative to other business entities.

Congress fixed this with the BBA, effective for tax years beginning January 1, 2018. Under the BBA, the IRS audits the partnership as a single entity. Any adjustment to partnership income, deductions, credits, or allocations is calculated at the partnership level. The resulting tax -- called the "imputed underpayment" -- is assessed against and collected from the partnership itself, not the individual partners.

This is a dramatic shift. Your partnership can now owe federal income tax even though it is a pass-through entity that technically does not pay income tax. And the bill can arrive years after the partners who triggered the liability have left the business.

How the Imputed Underpayment Works

The IRS multiplies the total net adjustment to partnership income by the highest applicable tax rate. In 2026, that is 37% for the individual rate.

The 37% rate applies regardless of the partners' actual brackets. If all four partners are in the 22% bracket, the partnership just paid a 37% rate on the adjustment. Partners can request modification of the imputed underpayment by providing documentation showing they are in lower brackets or are tax-exempt, but this requires prompt action during the audit.

The Partnership Representative: Your Single Point of Contact

Under the BBA, the partnership must designate a Partnership Representative (PR) for each tax year. The PR is the IRS's sole contact during an audit -- only the PR can receive notices, make elections, agree to adjustments, and settle. Individual partners have no right to participate and no right to receive audit notices directly.

If the PR makes a bad deal with the IRS, every partner is bound by it. Your partnership agreement should designate a specific PR, define the PR's authority to settle, address liability allocation for imputed underpayments, and include indemnification provisions for partners whose actions caused the problem. Many agreements written before 2018 have no PR provisions at all.

How to Opt Out: The Elect-Out Election

Smaller partnerships with the right partner mix can opt out of the BBA regime entirely. A partnership may elect out if: (1) it had 100 or fewer K-1 recipients for the year, and (2) each partner is an "eligible partner" -- an individual, C corporation, S corporation, estate of a deceased partner, or certain foreign entities.

If any partner is itself a partnership, LLC taxed as a partnership, or a trust, the elect-out fails entirely. The elect-out must be claimed annually on a timely-filed Form 1065 with an attached statement -- it is not automatic and does not carry forward.

The Push-Out Election: An Alternative to 37%

If your partnership cannot elect out, there is still a remedy after an audit concludes. The partnership can make a "push-out" election, shifting the adjustment to the partners who were in the partnership during the reviewed year. Those partners issue amended K-1s and pay tax at their own rates instead of the 37% entity-level rate.

The catch: the push-out election must be made within 45 days of receiving the notice of final partnership adjustment. Missing this window means the partnership pays the imputed underpayment at 37%. If your partnership is under audit, think about the push-out from day one -- not after the final notice arrives.

Who Is at Risk in 2026?

The IRS focuses partnership audits on large partnerships (assets over $10 million or income over $500,000), but the BBA applies to all partnerships regardless of size. Active compliance campaigns target real estate partnerships, hedge funds, and family limited partnerships. If your partnership has taken aggressive positions on cost segregation, depreciation, basis allocations, or expense deductions, those are the areas most likely to draw scrutiny.

Real estate partnerships should review positions carefully given IRS focus on this sector. For a comprehensive look at how real estate entity structures interact with audit risk and passive activity rules, see The Real Estate Tax Book.

S corporations are not subject to the BBA at all -- the IRS must audit S corp items through shareholders individually. If audit exposure is a key concern, the entity structure comparison is worth running. See The S Corp Tax Book for how S corps handle IRS scrutiny differently from partnerships.

Three Actions to Take Now

1. Check the elect-out eligibility. Review your partner roster and confirm every partner qualifies. If you qualify, make the election on this year's Form 1065 -- do not assume last year's carry forward.
2. Update your partnership agreement. Designate a PR, define their settlement authority, and address how imputed underpayments are allocated. Agreements predating 2018 almost certainly lack adequate BBA provisions.
3. Document your aggressive positions. Work with your advisor to stress-test depreciation schedules, basis allocations, and deductions before the IRS does. Amending a return voluntarily is almost always cheaper than defending a position in audit.

The BBA made partnerships far easier and more profitable for the IRS to audit. The tools are in place, and enforcement continues as an active priority. The best defense is a well-drafted partnership agreement, an annual elect-out where possible, and books that can withstand scrutiny.

For a complete treatment of partnership audit rules, the PR role, and entity-level tax planning, see Partnership Tax Strategies by AE Tax Advisors.