IRS Publication 501 — Dependents, Standard Deduction, and Filing Information

Spouse in combat zone. You can sign a joint return for your spouse if your spouse can’t sign because they are serving in a combat zone (such as the Persian Gulf area, Serbia, Montenegro, Albania, or Afghanistan), even if you don’t have a power of attorney or other statement. Attach a signed statement to your return explaining that your spouse is serving in a combat zone. For more information on special tax rules for persons who are serving in a combat zone, or who are in missing status as a result of serving in a combat zone, see Pub. 3.

Power of attorney (POA). In order for you to sign a return for your spouse in any of these cases, you must attach to the return a POA that authorizes you to sign for your spouse. You can use a POA that states that you have been granted authority to sign the return, or you can use Form 2848. Part I of Form 2848 must state that you are granted authority to sign the return. Nonresident alien or dual-status alien. Generally, a married couple can’t file a joint return if either spouse is a nonresident alien at any time during the year. However, you and your spouse can choose to be treated as U.S. residents for the entire year and file a joint return if one spouse was a nonresident alien at the end of the taxable year (the nonresident spouse) and the other was a U.S. citizen or resident at the end of the taxable year. This choice remains in effect in subsequent years until terminated. You and your spouse can also choose to file as U.S. residents for the entire year if both of you are U.S. citizens or residents at the end of the year and either (or both) of you were a nonresident at the beginning of the year (the dual -status spouse(s)). You can only make this choice for 1 year, and it doesn’t apply to any future years. If you and your spouse are making either of these choices to be treated as U.S. residents for 2025, check the box in the Filing Status section and enter the name of the nonresident spouse or dual -status spouse(s) (whichever applies to you) in the entry space. Also check the box and enter their name if you and your nonresident spouse made the choice to be treated as residents in a prior year and the choice remains in effect. See the Instructions for Form 1040 and Pub. 519 for more information on how to make this choice.