As long as you are legally married you have to file as either married filing jointly or married filing separately.
You are still considered married if you are living separately but are notlegally separated under a final divorce decree. Typically, you can file as either Married Filing Jointly (MFJ) or Married Filing Separately (MFS). Under certain circumstance you can file as Head of Household.
Answers are correct to the best of my ability but do not constitute legal or tax advice.
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