Filing your taxes as “Married Filing Separately” (MFS) comes with several unique rules, one of the most important being how the standard deduction is applied. For the 2025 tax year, the IRS continues to enforce the “both or neither” rule, which requires coordination between spouses. Let’s dive into how this rule works, when you can claim the standard deduction, and what exceptions may apply.
🔍 The “Both or Neither” Rule Explained
If you’re married and choose to file separately, the IRS requires that both spouses must either take the standard deduction or both must itemize deductions. You cannot mix the two approaches between spouses.
- If one spouse itemizes, the other spouse is automatically not allowed to claim the standard deduction.
- This rule prevents double-dipping and maintains consistency across jointly earned income and shared expenses.
📊 2025 Standard Deduction for MFS Filers
- Standard Deduction: $15,750 (per spouse filing separately)
- Additional for age 65+ or blind: $1,600 per condition
- Senior bonus (new 2025–2028 rule): Up to $6,000 extra deduction if under MAGI threshold
🧾 Example Scenarios
Example 1: John and Mary are married but file separately.
- John itemizes deductions because of high medical expenses.
- Mary wanted to take the standard deduction, but she cannot — she must also itemize, even if her itemized deductions are lower than the standard deduction.
Example 2: Sarah and Tom both agree to claim the standard deduction.
- Each files a separate return and claims the $15,750 standard deduction.
- If Sarah is 66, she also adds $1,600 for being age 65+, and possibly a $6,000 senior bonus if under the income threshold.
🚫 Exceptions to the Rule
- Innocent Spouse Relief: If you qualify for innocent spouse relief or are separated for part of the year, this may impact your filing strategy but doesn’t eliminate the “both or neither” requirement.
- Nonresident Alien Spouses: A U.S. taxpayer married to a nonresident alien can choose to file separately and still take the standard deduction under certain conditions.
- Abandoned Spouse Rule: If you lived apart from your spouse for the last six months of the year and maintain a household for a dependent, you may qualify to file as Head of Household and not be bound by the MFS rule.
📌 When Filing Separately Makes Sense
Although Married Filing Separately often results in a higher tax bill, it can be advantageous in the following situations:
- One spouse has significant medical or miscellaneous itemized deductions (which are limited based on AGI)
- You want to keep finances separate during divorce or separation
- One spouse is subject to default or liability issues (e.g., past-due child support or student loans)
📝 Filing Tips
- Coordinate with your spouse to determine whether you’ll both itemize or both take the standard deduction.
- Use tax software or consult a tax professional to calculate which strategy produces the lowest combined tax liability.
- Remember to include all income and deductions correctly on each return, especially for shared assets or community property states.
✅ Summary
If you’re married and filing separately in 2025, you can claim the standard deduction—but only if your spouse does the same. The “both or neither” rule ensures consistency in the filing process. If your spouse itemizes, you must itemize too, even if it results in a higher tax bill. Consider your household’s total tax position before choosing the MFS status.
Need help calculating your optimal filing method or determining whether to itemize? Share your scenario, and we’ll walk through it together.
