You can amend your tax return from Married Filing Jointly to Head of Household for 2020 if you do before April 15.
After that you do not have the option of amending to change to that filing status.
If you do amend to Head of Household, your husband will need to amend his tax return to file as Married Filing Separately (unless he also qualifies to file as Head of Household. He would need to be providing the home for a dependent that is claimed on his tax return just as you do).
Filing Status Changes
