@pk
@Almo2
So if I understand correctly and can summarize:
1. The spouse is a dual-status alien for 2024 and by default would file a 1040-NR that only reported US-source income (if any) up to the date of the GC, and a 1040 (as married filing separately) reporting all world-wide income after the date of the GC.
2. The taxpayer could file (or amend) for 2024 as married filing jointly by making the election to treat the spouse as a resident for the whole year. The taxpayer would have to test whether this actually benefits them in their situation.
3. The taxpayer can't amend to joint filing earlier years (2023 and back).
4. They can file jointly under the normal rules for 2025 and future.
