Retirement tax questions

Joint should still be better.  Do you get Social Security?  You get a higher standard deduction even if 1 spouse has no income.   Some reasons for Joint.  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.