How is the Missouri capital gain subtraction calculated on a Missouri combined return when the spouses file a joint federal return, and one spouse has a capital gain while the other spouse has a capital loss?

For the 2025 tax year, the portion of income treated as capital gain for federal income tax purposes, and included in federal adjusted gross income, is the amount shown on line 7a of the federal form 1040. If one spouse has a capital gain while the other spouse has a capital loss, the amount from federal form 1040, line 7a will be entered on Form MO-A, line 18Y or line 18S only for the spouse that had the gain.

Example:

Combined capital gain reported on federal form 1040, line 7a: $10,000

Primary taxpayer’s capital loss: $(5,000)

Secondary taxpayer’s capital gain: $15,000

Amount that should be entered on MO-A, line 18Y: $0

Amount that should be entered on MO-A, line 18S: $10,000

If you still have questions, please check out other Individual Income Tax FAQs .