@any_mouse the general rules for the exclusion is that either spouse can own it, but both must occupy it as their principal residence for 2 years of the 5 years before sale. Then they qualify for the maximum exclusion provided the other rules are complied with. They don't even need to occupy it as their principal residence at the same time. So, if they meet the ownership and occupancy test for the 2021 house they are entitled to the full $500,000 exclusion and would have to wait two years from the 2021 sale to sell another principal residence to qualify again for the full exclusion.
