If Married Filing Separately, Do Both Have to Itemize?

When married individuals choose to file separate tax returns, they opt for the “Married Filing Separately” status. Each spouse reports their own income, deductions, and credits on an individual tax return. While many married couples find it more advantageous to file jointly due to various tax benefits, filing separately can be a suitable option in specific situations. It generally offers each spouse independence regarding their tax liability.

The Itemization Requirement for Married Filers

A rule for married couples filing separately concerns how they claim deductions. If one spouse chooses to itemize deductions, the other spouse must also itemize deductions and cannot claim the standard deduction. The Internal Revenue Service (IRS) mandates this uniformity in deduction methods between spouses.

Itemizing deductions involves listing specific expenses, such as state and local taxes, mortgage interest, and charitable contributions, to reduce taxable income. In contrast, the standard deduction is a set dollar amount provided by the IRS that taxpayers can claim if they do not itemize. For example, for the 2025 tax year, the standard deduction for a single filer or married filing separately is $15,000. The rule requiring both spouses to itemize or both take the standard deduction prevents individuals from gaining an unfair tax advantage. It ensures spouses cannot selectively use the most beneficial deduction method, which could lead to a combined tax benefit greater than what a single household should receive.

Choosing Between Deduction Methods

Given the requirement for both spouses to use the same deduction method, a coordinated strategy becomes necessary when filing separately. Spouses should compare the total potential itemized deductions for each individual against their respective standard deduction amounts. This comparison helps determine which approach yields the lowest overall tax liability for the couple.

If one spouse has many itemized deductions, such as mortgage interest or unreimbursed medical expenses that exceed 7.5% of their adjusted gross income, it might be beneficial for both to itemize. This can hold true even if the other spouse’s individual itemized deductions are less than their standard deduction amount. The goal is to maximize the combined tax savings. Conversely, if both spouses have low itemized deductions, taking the standard deduction for both might be more prudent.

When expenses are paid from separate funds, the paying spouse generally claims that deduction. However, if expenses are paid from jointly owned funds, such as a joint checking account, the deduction should generally be split between both spouses. This careful allocation of deductions, coupled with an evaluation of each spouse’s income and potential deductions, helps ensure the most favorable tax outcome.

Circumstances Affecting the Deduction Choice

In community property states, income earned and assets acquired during marriage are generally considered jointly owned by both spouses. This means that even when filing separately, spouses in these states typically must report half of all community income and half of deductions paid from community funds on their individual returns. Nine states follow community property laws:

• Arizona
• California
• Idaho
• Louisiana
• Nevada
• New Mexico
• Texas
• Washington
• Wisconsin

An exception to the general rule exists when one spouse is a nonresident alien. If a U.S. citizen or resident is married to a nonresident alien, the U.S. spouse can choose to file as Married Filing Separately, and they may be able to claim the standard deduction. The nonresident alien spouse, who often has no U.S. tax obligation on foreign income, is not bound by the itemization rule. The default filing status for a U.S. citizen married to a nonresident alien is Married Filing Separately.

While not a direct exception to the itemization rule, the lack of coordination or failure to file a return by one spouse can create complications. If one spouse fails to file their tax return, the IRS might make a “deemed election” regarding their filing status or deductions, which could negatively impact the other spouse’s tax situation. This underscores the importance of both spouses actively participating in the tax filing process, even when filing separately.