Sorry you can't amend to MFS Married Filing Separately from Joint after the due date, April 15, 2025. You can amend to add his info and income to your Joint return. You may find Joint is better than MFS.
How to switch from Joint to Married filing separate
https://ttlc.intuit.com/turbotax-support/en-us/help-article/small-business-processes/switch-filing-j...
Here's some things to know about filing MFS
Many people think they come out better when filing Married Filing Separate but they are probably doing it wrong. If one person itemizes deductions then the other one must itemize too, even if it's less than the standard deduction, even if it is ZERO!
And there are several credits you can't take when filing separately, like the
EITC Earned Income Tax Credit
Child Care Credit
Educational Deductions and Credits
And contributions to IRA and ROTH IRA are limited when you file MFS.
Also if you file Married Filing Separately up to 85`% of your Social Security becomes taxable right away even with zero other income.
See …….
https://ttlc.intuit.com/community/married/help/is-it-better-for-a-married-couple-to-file-jointly-or-...
