Last year we filed as Married Filing Jointly. We underpaid taxes during the year, so we have been paying estimated taxes (jointly) throughout the year. This year, we have very disparate incomes and medical expenses so we are filing as Married Filing Separately. How should we each report the estimated taxes paid during the year? Proportionately based on our best estimate of how much of the AGI was for each of us? Simple numbers for an example: let's say we paid $10,000 total in estimated taxes during the year, and in 2019, we had a combined AGI of $100,000. Of the $100,000, $25,000 was my husband's income and $75,000 (75%) was my income. So in completing 2020 taxes, I would show $7,500 in estimated taxes paid and he will show $2,500. Is this conceptually correct?
