Getting married changes your federal taxes in three places at once: your tax brackets widen, your standard deduction roughly doubles, and your eligibility for several credits and deductions shifts based on whether you file jointly or separately. The IRS treats you as married for the entire tax year if you are legally married on December 31, no matter when the wedding happened.1Internal Revenue Service. Filing Status From that point forward, the size of your tax bill depends heavily on which married filing status you pick.
Joint or Separate: The Core Choice
A joint return combines both spouses’ income, deductions, and credits on a single Form 1040. It usually produces the lower tax bill because joint filers get wider brackets and the largest standard deduction available. The cost is joint and several liability: both spouses are legally responsible for the entire tax owed, even if only one earned the income or caused an error.2Office of the Law Revision Counsel. 26 USC 6013 – Joint Returns of Income Tax by Husband and Wife
Filing separately means each spouse reports only their own income and takes their own deductions.3Internal Revenue Service. Publication 501 (2025), Dependents, Standard Deduction, and Filing Information Your liability stops at your own return, which can matter if a spouse has unpaid debts, uncertain tax positions, or student loans on an income-driven repayment plan. But separate filing shuts you out of several credits and shrinks other tax benefits, and most couples pay more overall as a result.
Wider Brackets and a Bigger Standard Deduction
For 2026, joint filers stay in the 10 percent bracket on their first $24,800 of taxable income and remain in the 12 percent bracket up to $100,800.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 A single filer moves out of the 12 percent bracket at $50,400.5Office of the Law Revision Counsel. 26 USC 1 – Tax Imposed The complete 2026 schedule for married filing jointly:
- 10%: up to $24,800
- 12%: $24,801 to $100,800
- 22%: $100,801 to $211,400
- 24%: $211,401 to $403,550
- 32%: $403,551 to $512,450
- 35%: $512,451 to $768,700
- 37%: over $768,700
These wider brackets help most when one spouse earns significantly more than the other, because the higher earner’s income fills low-rate space the other spouse is not using. When two high earners combine incomes, the top brackets (35 and 37 percent) are not perfectly doubled, and the combined return can land in a higher bracket than either would face alone. That is the “marriage penalty,” and it mostly affects couples at the top of the income scale.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
The standard deduction moves the same way. Married couples filing jointly get $32,200 for 2026, exactly double the $16,100 for single filers. Married filing separately gets $16,100 per spouse. One catch: if your spouse itemizes on a separate return, you must itemize too. Your standard deduction drops to zero if you try to take it while your spouse itemizes.6Office of the Law Revision Counsel. 26 USC 63 – Taxable Income Defined
Credits That Change When You Marry
Many popular credits use income phase-outs, and marriage changes both the thresholds and, in some cases, your eligibility altogether.
Earned Income Tax Credit
If you are married, you can claim the EITC only on a joint return. Filing separately disqualifies you completely.7Office of the Law Revision Counsel. 26 USC 32 – Earned Income Joint filers get higher phase-out thresholds than single filers, but combining two incomes can still push a household past the limit.
Child Tax Credit
The Child Tax Credit is worth up to $2,200 per qualifying child for 2026. Joint filers can earn up to $400,000 in adjusted gross income before the credit phases out, twice the $200,000 threshold for other filing statuses. Above those limits, the credit shrinks by $50 for every $1,000 of additional income.8Internal Revenue Service. Child Tax Credit
Child and Dependent Care Credit
This credit helps cover care for a child under 13 or a dependent who cannot care for themselves while you work. On a joint return, the credit amount is capped at the lower-earning spouse’s income for the year.9Office of the Law Revision Counsel. 26 USC 21 – Expenses for Household and Dependent Care Services Necessary for Gainful Employment Married couples filing separately cannot claim it at all.
Premium Tax Credit
If you buy marketplace health coverage under the Affordable Care Act, filing separately generally disqualifies you from the premium tax credit.10Internal Revenue Service. Eligibility for the Premium Tax Credit A narrow exception exists for victims of domestic abuse or spousal abandonment, and for certain married people who lived apart from their spouse for the last six months of the year and qualify as head of household.
Deductions and Contribution Limits Cut by Separate Filing
Choosing separate returns costs you more than credits. Several core deductions and retirement rules also tighten.
Student Loan Interest
Married taxpayers who file separately cannot deduct any student loan interest. The statute requires a joint return.11Office of the Law Revision Counsel. 26 US Code 221 – Interest on Education Loans Joint filers can deduct up to $2,500 in interest, with a phase-out at higher incomes.
Capital Losses
If your investment losses exceed your gains, you can deduct up to $3,000 of the excess against ordinary income on a joint return. Filing separately cuts the limit to $1,500 per spouse.12Office of the Law Revision Counsel. 26 US Code 1211 – Limitation on Capital Losses
Roth IRA Contributions
This is one of the sharpest penalties for separate filing. Married couples filing jointly can make full Roth IRA contributions if their modified adjusted gross income is under $242,000 in 2026, with partial contributions allowed up to $252,000. Married filing separately, you can only make a partial contribution if your income is under $10,000, and nothing at all at $10,000 or above.13Internal Revenue Service. IRS Notice 2025-67 – 2026 Amounts Relating to Retirement Plans and IRAs
Medicare Premiums and Social Security
Marriage and filing status also reach beyond the income tax itself. Medicare Part B carries income-related surcharges, and the thresholds depend on how you file. For 2026, joint filers pay the standard Part B premium of $202.90 per month as long as their modified adjusted gross income stays at or below $218,000. Above that, per-person surcharges range from $81.20 to $487.00 per month, with the top tier hitting at $750,000. Married taxpayers filing separately face a much steeper structure: the standard premium applies only up to $109,000, and anyone between $109,000 and $391,000 jumps straight to a $446.30 monthly surcharge, skipping the intermediate tiers.14CMS. 2026 Medicare Parts A and B Premiums and Deductibles
Social Security benefits also become taxable at different combined-income thresholds. Joint filers see part of their benefits taxed once combined income exceeds $32,000; the threshold is $25,000 for individuals.15Social Security Administration. What You Need to Know When You Get Retirement or Survivors Benefits Married taxpayers filing separately will likely owe tax on their benefits regardless of income.
Filing as Head of Household While Married
Some married people can file as head of household, which gives a larger standard deduction ($24,150 for 2026) and wider brackets than married filing separately, and it preserves access to credits that separate filers lose.4Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 You must meet all of these:
- You file a return apart from your spouse.
- You and your spouse lived in separate homes for the entire last six months of the tax year.
- You paid more than half the cost of maintaining your home, including rent or mortgage, utilities, insurance, repairs, and food.
- Your home was the main residence of your dependent child, stepchild, or foster child for more than half the year.
Temporary absences for military service or education do not count as “living apart.” If you meet every condition, the IRS treats you as unmarried for filing purposes, which restores eligibility for credits like the EITC and premium tax credit.16Internal Revenue Service. Filing Status
If You Are Worried About Joint Liability
Because joint filers are each responsible for everything on the return, one spouse can end up owing tax caused by the other’s errors. The IRS offers three forms of relief:
- Innocent spouse relief, when your spouse understated the tax, you did not know about the error when you signed, and holding you liable would be unfair.
- Separation of liability, which allocates the understated tax between you and your former spouse. You must be divorced, legally separated, or have lived apart for at least 12 months before you request it.
- Equitable relief, a catch-all when you do not qualify for the other two. The IRS weighs factors like abuse, financial control, economic hardship, and later tax compliance. This is the only relief available for an unpaid tax, as opposed to an understated one.
You request relief by filing Form 8857. There is no fee, and you can file even while still married.17Internal Revenue Service. Instructions for Form 8857 Because filing jointly usually saves more than the liability risk costs, weighing this option before defaulting to separate returns is worthwhile.
If Your Spouse Is a Nonresident Alien
When one spouse is a U.S. citizen or resident and the other is a nonresident alien, the couple can elect to treat the nonresident spouse as a U.S. resident for tax purposes. That election lets you file jointly and use the wider brackets and credits described above.18eCFR. Election to Treat Nonresident Alien Individual as Resident of the United States You make the election by attaching a signed statement to the joint return for the first year it applies. It stays in effect until you formally terminate it, and both spouses must report worldwide income, including foreign earnings, on the U.S. return.