What Is the Married Filing Separately Standard Deduction?

Married Filing Separately (MFS) is a tax filing status that allows married couples to file individual tax returns. A key part of this status is the standard deduction, a set amount taxpayers can subtract from their adjusted gross income (AGI) to lower their taxable income. MFS is governed by specific regulations concerning the deductions each spouse can claim, which can influence whether filing separately is a financially sound decision.

Determining the Standard Deduction Amount

For the 2024 tax year, the standard deduction for an individual using the Married Filing Separately status is $14,600, and this amount increases to $15,000 for the 2025 tax year. This figure is set by the IRS and adjusted periodically for inflation, allowing a taxpayer to reduce their taxable income without needing to itemize deductions.

A primary regulation governing the MFS standard deduction is the consistency requirement between spouses. If one spouse chooses to itemize their deductions—listing out expenses like mortgage interest or state taxes—the other spouse is automatically disqualified from taking the standard deduction. In this scenario, the second spouse’s standard deduction becomes $0, and they must also itemize any deductions they wish to claim. This rule prevents a couple from gaining an unfair advantage by having one spouse itemize large deductions while the other still benefits from the full standard deduction.

For example, consider a couple where one spouse has significant business expenses and chooses to itemize to deduct them. The other spouse, who may have few or no itemizable expenses, loses the ability to claim the $14,600 standard deduction for 2024. Their standard deduction is reduced to zero, potentially increasing their individual tax liability.

Taxpayers who are age 65 or older or are legally blind are entitled to an additional standard deduction amount. For 2024, this additional amount for an MFS filer is $1,550. A person who is both over 65 and blind can claim this additional amount twice, for a total of $3,100. This supplement is added to the base standard deduction.

Itemized Deductions for MFS Filers

When a spouse is ineligible for the standard deduction, they must itemize. Itemized deductions are specific, eligible expenses that the IRS allows taxpayers to subtract from their AGI. For MFS filers, the rules for claiming these deductions depend on which spouse paid the expense and the source of the funds used.

Common itemized deductions include state and local taxes (SALT), home mortgage interest, charitable contributions, and medical expenses. The SALT deduction is capped at $10,000 per household, so for MFS filers, this limit is divided, allowing each spouse to deduct a maximum of $5,000. The deduction for home mortgage interest is limited to interest paid on up to $375,000 of mortgage debt for each MFS filer, half of the $750,000 limit for joint filers.

The allocation of these deductions between spouses is based on payment responsibility. If an expense is paid from a joint bank account, the deduction is typically split evenly, 50/50, between the spouses. If an expense is paid from a spouse’s separate account, that individual is the one who claims the entire deduction. This requires record-keeping to substantiate which spouse is entitled to which deduction.

Medical expenses can also be itemized, but only the amount that exceeds 7.5% of a taxpayer’s AGI is deductible. For MFS filers, each spouse must calculate this threshold based on their own separate AGI. This can be advantageous if one spouse has a much lower AGI and significant medical bills, making it easier to surpass the 7.5% floor compared to a higher combined AGI on a joint return.

Deciding Between Filing Statuses

Choosing between Married Filing Separately and Married Filing Jointly requires an analysis of a couple’s financial picture. While the MFS status often results in a higher combined tax liability due to less favorable deduction rules, certain situations can make it the more strategic choice. The decision hinges on whether the benefits of filing separately outweigh the loss of certain tax advantages.

A common reason for choosing MFS is to manage federal student loan payments under an income-driven repayment (IDR) plan, such as the SAVE plan. Under these plans, monthly payments are calculated based on discretionary income, which is derived from AGI. When filing jointly, the combined AGI of both spouses is used, which can lead to a much higher monthly student loan payment. By filing separately, only the borrower’s individual AGI is considered, potentially lowering the payment.

For instance, if one spouse earns $60,000 and the other earns $100,000 with a large student loan balance, filing jointly would base the loan payment on a $160,000 AGI. Filing separately would base the payment on only the $100,000 AGI of the borrowing spouse. The monthly savings on the student loan payment could easily exceed the additional income tax incurred from filing separately, resulting in a net financial gain for the household.

Another scenario involves high medical expenses for one spouse. As the medical expense deduction is limited to costs exceeding 7.5% of AGI, a lower individual AGI on an MFS return can make it possible to claim a deduction. If a couple’s combined AGI is too high to meet this threshold on a joint return, separating their incomes may allow the spouse with high medical costs to deduct thousands of dollars, reducing their individual tax burden.