You need to file Joint and submit the injured spouse form with your return.
As you found out, It is usually better to file Joint. Joint has the lowest tax rates and the highest Standard Deduction. And if you are in a Community Property state MFS gets tricky to figure out. And 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-...
