Simple answer: you file as Married Filing Jointly (MFJ) unless you have a specific reason for filing separately (MFS).
Even if you think you have a reason to file MFS, you should state what those reasons are, in this forum, and somebody may be able to help you with a work around.
A common example: your spouse owes back child support or student loan debt and you're afraid the IRS will take your refund. Solution: you still file jointly but with the "Injured Spouse" form.
