How is the Qualified Business Income (QBI) deduction calculated for a partner in a partnership for the 2025 tax year?

The Qualified Business Income (QBI) deduction, established under Section 199A of the Internal Revenue Code, allows eligible owners of pass-through entities (sole proprietorships, S corporations, partnerships, and some trusts/estates) to deduct up to 20% of their qualified business income. For a partner in a partnership, the calculation involves several layers of complexity based on income thresholds and the nature of the business activity in 2025.

### Step 1: Determine Qualified Business Income (QBI)

QBI is the net amount of qualified items of income, gain, deduction, and loss from any qualified trade or business (QTB) of the taxpayer. For a partner, this is their distributive share of the partnership’s income, excluding certain items like capital gains, guaranteed payments for services rendered, and investment income.

### Step 2: Apply the Taxable Income Thresholds

The application of limitations depends entirely on the taxpayer's total taxable income (before the QBI deduction). For 2025, assuming the Tax Cuts and Jobs Act (TCJA) provisions remain in place, the thresholds are indexed for inflation. Let's use hypothetical 2025 brackets (actual 2025 figures would be confirmed by IRS inflation adjustments):

A. Below the Lower Threshold: If the partner's taxable income is below the lower threshold, the deduction is simply 20% of their total QBI from all sources, regardless of whether the business is a Specified Service Trade or Business (SSTB).

B. Above the Upper Threshold: If the partner's taxable income exceeds the upper threshold, the deduction is subject to two major limitations:

• SSTB Limitation: If the partnership is an SSTB (e.g., health, law, accounting, consulting), the QBI deduction is eliminated entirely.
• W-2 Wages and Unadjusted Basis of Assets (UBIA) Limitation: If the business is not an SSTB, the deduction is limited to the greater of:
• 50% of the W-2 wages paid by the partnership attributable to the partner's share of the business, OR
• 25% of the W-2 wages paid by the partnership attributable to the partner's share, plus 2.5% of the unadjusted basis immediately after acquisition (UBIA) of qualified property.

C. Between the Thresholds (Phase-In Range): If income falls in the range between the lower and upper thresholds, the deduction is phased in. The SSTB restriction begins to apply, and the W-2/UBIA limitation is partially applied.

### Partner Reporting

The partnership issues Schedule K-1 (Form 1065) to the partner, which clearly segregates the partner’s share of QBI, W-2 wages paid, and UBIA. The partner then uses Form 8995, Qualified Business Income Deduction, to compute the final deduction based on their individual tax return status and total taxable income.

It is vital for partners to coordinate with their partnership's tax preparer to ensure the K-1 accurately reflects the necessary components for the QBI calculation.