An HSA is owned by one specific person. IRAs are also only owned by one person. So spouse A can fund their HSA from an IRA owned by spouse A, and spouse B can fund their HSA from an IRA owned by spouse B. You can't cross the funding streams. And, you must respect the funding maximums. If you do an QHSAFD for spouse A in 2026 of $8750+$1000, that is the maximum for the year for both of you, except that spouse B could contribute their $1000 catch-up amount if over age 55. (But since spouse B can only perform one lifetime QHSAFD, that $1000 contribution should be from other funds, if spouse B wants to make a QHSAFD in 2027.)
