Marriage is a personal milestone—but it can also have significant financial consequences when it comes to taxes. While many couples assume that getting married leads to better tax benefits, that’s not always the case. Some couples end up paying more in taxes than they would if they remained single, due to what’s known as the marriage tax penalty.
The marriage tax penalty occurs when a married couple filing jointly pays more in taxes than they would if each person filed as a single taxpayer. This penalty typically affects couples with similar incomes and higher earnings, especially when tax brackets and deductions don’t scale evenly between single and married statuses.
This article explains how the marriage tax penalty works, why it happens, who is most likely to be affected, and the strategies couples can use to minimize its tax impact.
What is the Marriage Tax Penalty?
The marriage tax penalty refers to the additional tax burden some couples face when they marry and file jointly. Essentially, it’s the situation where two people pay more in taxes as a married couple than they would have if they filed as two single individuals.
The penalty is most likely to arise when both spouses earn similar and relatively high incomes. Because the U.S. tax code uses progressive tax brackets, combining incomes can push the couple into a higher tax bracket than they would be in individually.
It’s worth noting that not all married couples face a penalty. Some receive a marriage bonus, especially when one spouse earns significantly more than the other. The tax system in those cases allows for income to be spread across lower brackets, resulting in a lower overall tax bill.
However, when both partners earn similar amounts—particularly if they are high earners—filing jointly can create an unfavorable tax outcome.
Causes of the Marriage Tax Penalty
There are several structural reasons in the tax code that create the marriage tax penalty for certain couples:
- Uneven tax bracket thresholds – The tax brackets for married couples are not always double those of single filers. While lower brackets are generally aligned, the top brackets kick in sooner for married couples, causing more income to be taxed at a higher rate.
- Cap on deductions and credits – Certain tax benefits phase out at lower income levels for joint filers than for two single filers combined. This includes deductions for student loan interest, itemized deductions, and education credits.
- AMT and NIIT thresholds – The Alternative Minimum Tax (AMT) and Net Investment Income Tax (NIIT) also have thresholds that are not fully doubled for married couples. This can result in additional tax liability when filing jointly.
- Medicare surtaxes – High-income earners pay an additional 0.9% Medicare surtax on wages and 3.8% on investment income, with income thresholds of $250,000 for married couples—just $125,000 per person—compared to $200,000 for single filers.
- Phaseouts for tax credits – Credits like the Child Tax Credit, Earned Income Tax Credit, and Premium Tax Credit phase out at lower income levels for joint filers than they do when incomes are split across two returns.
These structural issues can combine to create a significant difference in tax liability, especially for dual-income couples earning six figures each.
Examples of Who Is Affected by the Marriage Tax Penalty
The marriage tax penalty does not apply to every couple, but it disproportionately affects certain income levels and employment situations. Here are some examples:
- Two high earners with similar incomes: Imagine two single individuals who each earn $175,000. As single filers, they’re taxed separately. But when they marry and file jointly with a combined income of $350,000, more of their income falls into higher brackets, increasing their overall tax bill.
- Dual-income households with children: A married couple earning a combined $300,000 with two children may lose access to the full Child Tax Credit, which phases out for joint filers starting at $400,000. If they each earned $150,000 and filed separately (as single filers), they might avoid the phaseout entirely.
- Couples paying student loan interest: Single filers can deduct up to $2,500 of student loan interest if their income is below $85,000. For married couples, the deduction phases out starting at $145,000 combined—effectively reducing the benefit for dual-income households.
- High earners with investment income: A couple with combined investment income over $250,000 will be hit with the 3.8% Net Investment Income Tax, even if individually they wouldn’t exceed the threshold as single filers.
Each of these examples highlights how combining incomes can inadvertently trigger new taxes or reduce access to valuable deductions.
Mitigating the Marriage Tax Penalty
While the marriage tax penalty can’t always be eliminated, couples can take steps to reduce its impact through smart tax planning.
- Evaluate filing status options: Most married couples file jointly, but in some cases, married filing separately (MFS) can reduce the tax burden—especially when one spouse has high deductions or student loan repayment is based on individual AGI. However, MFS also disqualifies you from many credits and deductions, so evaluate this option carefully with a tax professional.
- Adjust income timing: If possible, couples can time the receipt of income, bonuses, or capital gains to avoid crossing into higher brackets. For example, deferring income to the following tax year can help reduce the current year’s joint taxable income.
- Max out retirement contributions: Contributing to 401(k) plans, IRAs, and HSAs reduces taxable income and helps manage AGI. This strategy is particularly useful for high earners looking to drop into lower brackets.
- Use tax-efficient investments: Holding investments in tax-advantaged accounts like Roth IRAs or municipal bonds can reduce exposure to the Net Investment Income Tax and other surtaxes.
- Plan charitable giving: Donating appreciated assets, using donor-advised funds, or making qualified charitable distributions (QCDs) from IRAs can help reduce taxable income while supporting causes you care about.
- Monitor credit and deduction phaseouts: Keep an eye on income thresholds for common credits and deductions. Planning ahead can help preserve eligibility or allow you to shift expenses into years when they’re most beneficial.
- Work with a tax advisor: Given the complexity of the tax code and how it affects married couples differently based on income, deductions, and filing status, working with a tax professional is one of the best ways to reduce or manage the penalty.
Need Assistance with the Marriage Tax Penalty?
The marriage tax penalty is a real and sometimes surprising issue for couples with similar incomes or dual earners in higher brackets. While marriage often brings legal and financial benefits, it can also create new tax challenges when not properly planned for.
Understanding how your income is taxed as a couple—and knowing where your tax brackets, deductions, and credits may change—is key to minimizing the impact of the penalty.
At Dimov Tax, we help married couples navigate the tax code with personalized strategies tailored to your income and goals. Whether you’re newly married or planning ahead, our team can help you optimize your tax situation and keep more of what you earn.
Contact Dimov Tax today to develop a smart, penalty-aware tax plan built for your household.