Many states restrict joint state tax filing. For example, Massachusetts only allows married couples to file jointly if they share the same tax period in the state. Maryland, however, is more flexible: it allows married couples who filed a joint federal return to file a joint Maryland return, per the 2024 State & Local Tax Forms & Instructions, even if the spouses have different tax periods, live in different local taxing areas, or even different states.

However, just because joint filing is allowed does not mean it is always straightforward. Maryland has local taxes, and when spouses have different residency statuses or localities, calculating the correct local tax can be complex. In such cases, the return often must be filed by mail, with manual calculations for each spouse’s local tax.

Special Case: One Spouse is a Nonresident of Maryland

The relevant guidance is found in Administrative Release 3 (now called Technical Bulletin 3):

Specifically, the pro forma Maryland Form 505 is completed using the figures from the joint federal return for lines 1 through 31 (all form references refer to the 2011 tax year). On Maryland Form 505NR, the amount reported on line 7 should include the amount of the joint federal adjusted gross income that is attributable to the Maryland resident spouse. The total Maryland tax figure from line 32c of Form 505 should be added to the figures on lines 28 and 33 of Form 502, and that total should be entered on line 34 of Form 502. The remainder of Maryland Form 505, lines 33 through 55c, should be left blank.

Form 502 should be completed using the figures from the joint federal return. The amount of the joint federal adjusted gross income attributable to the nonresident spouse should be entered on line 12 of Form 502.

In practice, this means:

  • The taxpayers should file a resident return on Form 502 plus a pro forma nonresident return on Form 505 and Form 505NR.
  • On both the resident and nonresident returns, they should report the joint income on federal return.
  • On the resident return (Form 502), they should subtract the nonresident spouse’s income on line 12.
  • On the nonresident return (Form 505NR), they should subtract the resident spouse’s income on line 7 and prorate the deduction and exemption based on the Maryland source income ratio.
  • The total Maryland tax on the nonresident return (Form 505, line 32c) should be added to the local tax (Line 28 of Form 502). This is unusual, but it is what the guideline says. Line 33 and 34 of Form 502 are increased accordingly as Line 28 is part of it.

When the nonresident spouse has no Maryland source income, the nonresident return results in nothing to add to the resident return. The effect is they file a joint return as if the nonresident spouse is a resident but with no income. This is beneficial for the taxpayers as the joint filing status affords them with double deduction and exemption while with no additional taxes added.