# 2026 federal tax source checks

Verified September 4, 2026. Scope: single or married filing jointly, ordinary W-2 compensation and taxable brokerage investments. These are calculation references, not a claim that every provision below is implemented. Some general-rule publications remain labeled 2025; use the separately verified 2026 amounts.

## Income rates and deduction

| Rate | Single lower boundary | Married joint lower boundary |
| --- | ---: | ---: |
| 10% | $0 | $0 |
| 12% | $12,400 | $24,800 |
| 22% | $50,400 | $100,800 |
| 24% | $105,700 | $211,400 |
| 32% | $201,775 | $403,550 |
| 35% | $256,225 | $512,450 |
| 37% | $640,600 | $768,700 |

These boundaries apply to taxable income. Standard deductions are $16,100 single and $32,200 joint. Source: [IRS 2026 inflation announcement](https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill).

## Investments

The 0% long-term gain ceiling is $49,450 single / $98,900 joint; the 15% ceiling is $545,500 / $613,700. Above that, the regular preferential rate is 20%. The 2026 child tax credit maximum is $2,200, with up to $1,700 potentially refundable. Source: [Revenue Procedure 2025-32, sections 3.03 and 3.05](https://www.irs.gov/irb/2025-45_IRB).

Qualified dividends and net long-term gains stack above ordinary taxable income. Deduction amounts exceeding ordinary income can reduce the preferential portion. The worksheet also caps this tax at the tax computed using ordinary rates on all taxable income. Source: [2026 Publication 505, Worksheet 2-7](https://www.irs.gov/publications/p505).

Net short-term and long-term gains/losses separately, including carryovers, then offset opposite-signed net amounts. Net capital losses can reduce other income by up to $3,000 annually ($1,500 married separate); unused losses carry forward. Qualified dividends do not enter capital-loss netting. Taxable interest and nonqualified dividends use ordinary rates. Treasury interest is federally taxable but exempt from state/local income taxes. Source: [Publication 550](https://www.irs.gov/publications/p550).

NIIT is 3.8% of the lesser of net investment income and MAGI above $200,000 single / $250,000 joint, floored at zero. Wages are excluded from investment income but contribute to MAGI. Investment expenses and foreign income adjustments can change the base. Source: [IRS NIIT explanation](https://www.irs.gov/individuals/net-investment-income-tax).

## Retirement and payroll

2026 employee 401(k) deferrals: $24,500. IRA contribution limit: $7,500 plus $1,100 at age 50+. Traditional IRA deduction MAGI phaseouts: covered single contributor $81,000–$91,000; covered joint contributor $129,000–$149,000; uncovered contributor with covered spouse $242,000–$252,000. Roth IRA contribution phaseouts: single $153,000–$168,000, joint $242,000–$252,000. Source: [Notice 2025-67](https://www.irs.gov/irb/2025-49_IRB).

Traditional IRA contribution eligibility and deductibility are different. When neither spouse is covered at work, no income-based deduction phaseout applies. Source: [IRS IRA deduction limits](https://www.irs.gov/retirement-plans/ira-deduction-limits).

For a partial IRA deduction, reduce the annual limit using the phaseout range, round upward to $10, and apply a $200 minimum while inside the range; then cap by actual contribution and compensation. Compute spouses separately and use MAGI before IRA deductions. Source: [Publication 590-A, deduction worksheets](https://www.irs.gov/publications/p590a).

HSA limits are $4,400 self-only / $8,750 family, including employer contributions. Eligibility depends on coverage, not filing status. Qualified transit/vanpool and parking each have a $340 monthly exclusion. Qualifying employer health benefits and these transportation benefits are generally exempt from federal income and payroll taxes. Source: [2026 Publication 15-B](https://www.irs.gov/publications/p15b).

HSA salary reductions under a section 125 cafeteria plan avoid payroll tax; an ordinary payroll deduction alone does not. Direct personal HSA contributions do not reduce payroll-tax wages. Source: [2026 Publication 15](https://www.irs.gov/publications/p15).

Social Security wage base: $184,500 per worker, maximum employee Social Security tax $11,439. Do not combine spouses under one cap. Source: [SSA contribution and benefit base](https://www.ssa.gov/oact/cola/cbb.html).

## Itemized deductions and family credits

2026 SALT cap is $40,400 single/joint, with MAGI phaseout starting at $505,000 and a $10,000 cap floor. Itemized charity has a 0.5% AGI floor. Overall itemized deductions may also be reduced at high income: Publication 505 Worksheet 2-6 uses 5.4% of the smaller of itemized deductions or income above the top-bracket boundary after specified deductions. Source: [2026 Publication 505](https://www.irs.gov/publications/p505).

The SALT cap reduction is 30% of excess MAGI. The deduction is the smaller of eligible taxes paid and the resulting cap. Medical deductions have a 7.5% AGI floor; mortgage interest requires eligible debt and applicable debt limits. Source: [Schedule A instructions, general mechanics](https://www.irs.gov/instructions/i1040sca). Apply the 2026 SALT amounts above, not the 2025 amounts in those instructions.

Non-itemizers can deduct eligible cash gifts up to $1,000 single / $2,000 joint beginning in 2026. Source: [IRS charitable contributions topic](https://www.irs.gov/taxtopics/tc506). This reduces taxable income, not AGI; [Publication 505](https://www.irs.gov/publications/p505) places it with the standard deduction.

Full child tax credit eligibility includes age under 17, dependency, residency and valid Social Security number rules. Phaseout starts at $200,000 single / $400,000 joint. Source: [IRS child tax credit](https://www.irs.gov/credits-deductions/individuals/child-tax-credit). Reduction is $50 per $1,000 or fraction above the threshold: [26 USC 24](https://usc-cdn.house.gov/view.xhtml?edition=prelim&req=granuleid%3AUSC-prelim-title26-section24).

## Estimate boundaries

Do not present a regular-tax estimate as a complete return. Explicitly disclose unsupported AMT, refundable credits, dependent-care coordination, age-based provisions, foreign tax credits, investment-interest elections, wash-sale/basis adjustments, special-rate gains, loss carryover worksheets, and state-specific investment rules. State/local amounts need their own jurisdictional verification. Actual liability is different from paycheck withholding or a projected refund. Brokerage gains are not gross sale proceeds, and reinvested income is not necessarily spendable cash.