Tax Benefit Phase-Outs: Thresholds, Credits, and Deductions

Tax benefit phase-outs are the sliding scales built into the tax code: as your income climbs past a set floor, specific credits and deductions shrink, and above a ceiling they disappear entirely. For 2026, the floors range from around $10,860 for the childless Earned Income Tax Credit to $1,000,000 for the Alternative Minimum Tax exemption on a joint return. A dollar of income in the wrong range can cost you far more than the tax on that dollar, because it simultaneously erodes the benefits that were lowering your bill.

The Three Parts of a Phase-Out

Every phase-out has a floor, a range, and a ceiling. The floor is the income level where the benefit starts shrinking. The ceiling is where it disappears. The range in between is where the math happens, and the rate at which the benefit drops depends on the provision. The Child Tax Credit loses $50 for every $1,000 of income above the floor, a 5% reduction rate.¹ A taxpayer $10,000 above the floor loses $500 of credit. Someone $50,000 above loses $2,500.

Some benefits use a cliff structure instead. A cliff eliminates the entire benefit the moment income crosses a single threshold, with no partial credit. The Premium Tax Credit’s 400% of federal poverty level cap works this way: one extra dollar of income means losing thousands in insurance subsidies.

Most thresholds adjust each year for inflation through a revenue procedure the IRS publishes each fall. Revenue Procedure 2025-32 sets the 2026 figures.² Some numbers don’t move at all. The Additional Medicare Tax threshold has been fixed at $200,000 since 2013, and the Child Tax Credit floor is set by statute. When thresholds stay flat while wages rise, more taxpayers get pulled into phase-out territory every year.

Which Income Number Triggers the Phase-Out

Most benefits use one of two income measures: adjusted gross income (AGI) or modified adjusted gross income (MAGI).

AGI is your total income minus a specific list of adjustments spelled out in the tax code — retirement contributions, educator expenses, student loan interest, health savings account contributions, and others.³ It appears on the bottom of the first page of Form 1040.

MAGI adds certain excluded income back to AGI, most commonly foreign earned income, tax-exempt interest, and savings bond interest used for education.⁴ The tricky part: each tax provision can define “modified” slightly differently. Your MAGI for education credits may differ from your MAGI for IRA deductions. If you are close to a threshold, check which version applies to the specific benefit.

2026 Phase-Outs for Credits

Credits hit harder than deductions when they phase out. A credit reduces tax dollar-for-dollar, so losing $500 of credit means paying $500 more. Losing $500 of deduction only costs $500 times your marginal rate.

Child Tax Credit

For 2026, the Child Tax Credit is worth up to $2,500 per qualifying child under 17.⁵ It begins to shrink at $200,000 of MAGI for single filers and $400,000 for joint filers, dropping $50 for every $1,000 above those floors.¹ A single parent with one child loses the full credit at $250,000. A married couple with two children keeps some credit until income reaches $500,000.

Earned Income Tax Credit

The EITC has the most complex structure of any major credit. It phases in as income rises from zero, plateaus at a maximum, then phases out. Every parameter changes with the number of qualifying children. For 2026:²

Three or more children: maximum $8,231, phase-out from $23,890 single ($31,160 joint) to $62,974 single ($70,244 joint).
Two children: maximum $7,316, phase-out from $23,890 single ($31,160 joint) to $58,629 single ($65,899 joint).
One child: maximum $4,427, phase-out from $23,890 single ($31,160 joint) to $51,593 single ($58,863 joint).
No children: maximum $664, phase-out from $10,860 single ($18,140 joint) to $19,540 single ($26,820 joint).

The phase-out rate for workers with children runs between about 16% and 21% of every extra dollar.⁶ Combined with regular income tax and payroll tax, effective marginal rates in the phase-out zone can exceed 50%.

Education Credits

The American Opportunity Tax Credit is worth up to $2,500 per eligible student for the first four years of college. You get the full amount with MAGI at or below $80,000 ($160,000 joint), a proportional reduction between $80,000 and $90,000 ($160,000 and $180,000 joint), and nothing above $90,000 ($180,000 joint).⁷ These thresholds are not indexed for inflation and have been static for years.

The Lifetime Learning Credit uses the same income limits and covers a broader set of expenses, including graduate school and professional development, with a maximum of $2,000 per return.⁸ You cannot claim both credits for the same student in the same year.

Saver’s Credit

The Saver’s Credit uses tiered rates rather than a smooth phase-out. For 2026, married couples filing jointly get a 50% credit on eligible retirement contributions with AGI at or below $48,500, 20% between $48,501 and $52,500, 10% between $52,501 and $80,500, and zero above. Single filers hit those same drops at $24,250, $26,250, and $40,250.

Premium Tax Credit

The Premium Tax Credit subsidizes health insurance bought through the federal marketplace. The enhanced subsidy that removed the upper income cap expired on January 1, 2026 and was not renewed.⁹ For 2026, the 400% of federal poverty level ceiling is back. A single person above roughly $62,600 or a family of four above $128,600 loses all premium subsidies. This is a cliff. Earning one dollar over the line means repaying the entire subsidy at tax time.

2026 Phase-Outs for Deductions

Student Loan Interest

You can deduct up to $2,500 of interest paid on qualified education loans.¹⁰ The 2026 phase-out begins at $85,000 of MAGI for single filers ($175,000 joint) and ends at $100,000 ($205,000 joint).² A single filer with MAGI of $92,500, halfway through the $15,000 range, can deduct $1,250 instead of the full $2,500.

Traditional IRA Contributions

If you or your spouse is covered by a workplace retirement plan, your ability to deduct a traditional IRA contribution depends on income. For 2026, a single filer or head of household covered by a workplace plan faces a phase-out between $81,000 and $91,000 of AGI. For joint filers where the contributing spouse has a workplace plan, the range is $129,000 to $149,000.¹¹ These ranges are narrow: $10,000 for singles, $20,000 for joint filers.

You can still contribute to a traditional IRA above these limits. You just cannot deduct the contribution, and the money goes in after tax.

Qualified Business Income

The qualified business income deduction lets owners of pass-through businesses deduct up to 23% of qualified business income for 2026, up from 20%.⁵ The phase-out depends on whether the business is a specified service trade or business (SSTB), which includes law, medicine, consulting, accounting, and financial services.

For 2026, the phase-out begins at approximately $200,000 of taxable income for single filers ($400,000 joint). The deduction is reduced by 75 cents for every extra dollar of taxable income until the wage and capital limitations apply fully.¹² The range extends $75,000 for singles and $150,000 for joint filers. SSTB owners above the ceiling lose the deduction on service income entirely. Non-SSTB owners keep a partial deduction based on wages paid and property owned.

Roth IRA Contribution Limits

Roth IRAs do not offer a deduction, but the ability to contribute at all phases out with income. For 2026, single filers can make full contributions with MAGI below $153,000, a reduced amount between $153,000 and $168,000, and no direct contribution above $168,000. Joint filers face a phase-out between $242,000 and $252,000.¹¹

Above the ceiling, the backdoor Roth strategy (contributing to a traditional IRA and converting to Roth) remains available, though it adds complexity and potential tax consequences if you hold other pre-tax IRA balances.

Surtaxes That Phase In

Two additional taxes work in reverse. Instead of losing a benefit, you gain a tax as income rises. The practical effect is the same.

A 0.9% Additional Medicare Tax applies to wages and self-employment income above $200,000 for single filers, $250,000 for joint filers, and $125,000 for married filing separately.¹³ Employers withhold the extra tax on wages above $200,000 regardless of filing status.¹⁴ Joint filers with combined income below $250,000 claim the excess back on the return. These thresholds are not indexed for inflation.

The 3.8% Net Investment Income Tax applies to the lesser of net investment income or the amount by which MAGI exceeds $200,000 single, $250,000 joint, or $125,000 married filing separately.¹⁵ Investment income includes interest, dividends, capital gains, rental income, and royalties. These thresholds have never been adjusted for inflation.

The Alternative Minimum Tax exemption also phases out. For 2026, the exemption is $90,100 for single filers and $140,200 for joint filers, with the phase-out beginning at $500,000 single and $1,000,000 joint.¹⁶ The exemption drops 25 cents per dollar above those floors and disappears at $860,400 single, $1,560,800 joint.

How Filing Status Changes the Numbers

Filing status determines which set of thresholds applies, and the joint threshold is not always double the single one. When it is less than double, a two-earner couple faces a marriage penalty: their combined income hits the phase-out sooner than it would if they filed as two singles.

The Child Tax Credit avoids this by setting the joint floor ($400,000) at exactly twice the single floor ($200,000).¹ The NIIT and Additional Medicare Tax do not. The single threshold is $200,000; the joint threshold is $250,000 rather than $400,000. Two people each earning $150,000 owe no Additional Medicare Tax as singles but owe it on $50,000 of combined income if they marry and file jointly.

Married filing separately almost always produces the worst thresholds. It disqualifies you from the EITC and education credits entirely, and the NIIT threshold drops to $125,000, half the joint amount. The status rarely helps from a phase-out perspective unless one spouse has specific circumstances like income-driven student loan repayment calculations.

Staying Below a Threshold

Because most phase-outs are triggered by AGI or MAGI, anything that lowers those figures pushes you further from the line. The most effective tools are above-the-line deductions, which come out before AGI is calculated.¹⁷

Workplace retirement contributions. Money put into a traditional 401(k), 403(b), or similar plan reduces W-2 income before it reaches AGI. The 2026 elective deferral limit is $23,500, with a $7,500 catch-up for workers 50 and older.
Health savings account contributions. If you have a high-deductible health plan, HSA contributions lower AGI and grow tax-free.
Traditional IRA contributions. Even when the deduction phases out, a deductible contribution still lowers MAGI for other purposes.
Self-employed retirement plans. SEP-IRAs and solo 401(k) plans allow much larger contributions than individual accounts, useful for business owners near the QBI or education credit thresholds.

Timing matters as much as the strategy. Near a phase-out floor, accelerating deductible expenses into the current year or deferring income into the next can keep you below the line. Charitable donations bunched into one year through a donor-advised fund can push itemized deductions high enough to make a meaningful difference. The goal is not to earn less. It is to control when income lands on your return and which adjustments you claim in which year.

1
Tax Policy Center. What Is A Tax Credit Phaseout
2
Internal Revenue Service. Revenue Procedure 2025-32
3
Office of the Law Revision Counsel. 26 USC 62 – Adjusted Gross Income Defined
4
Internal Revenue Service. Modified Adjusted Gross Income
5
House Ways and Means Committee. The One Big Beautiful Bill Section by Section
6
Office of the Law Revision Counsel. 26 USC 32 – Earned Income
7
Internal Revenue Service. American Opportunity Tax Credit
8
Internal Revenue Service. Education Credits – AOTC and LLC
9
Library of Congress Congressional Research Service. Enhanced Premium Tax Credit and 2026 Exchange Premiums
10
Office of the Law Revision Counsel. 26 USC 221 – Interest on Education Loans
11
Internal Revenue Service. 2026 Amounts Relating to Retirement Plans and IRAs
12
Office of the Law Revision Counsel. 26 USC 199A – Qualified Business Income
13
Internal Revenue Service. Topic No. 560, Additional Medicare Tax
14
Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
15
Internal Revenue Service. Topic No. 559, Net Investment Income Tax
16
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
17
Internal Revenue Service. Lowering AGI This Year Can Help Taxpayers When They File Next Year