I am still legally married, but live apart from my spouse because of domestic abuse or abandonment. I cannot file a joint tax return. Can I qualify for premium tax credits if I file as married-filing-separately and don’t take into account my spouse’s income?

Yes.  If you are married but unable to file a joint return because of domestic abuse, you can file as married-filing-separately and claim the premium tax credit.  Similarly, if you cannot file a join return because you are unable to locate your spouse due to spousal abandonment, you can file as married-filing-separately and claim the premium tax credit.  In either instance, you will need to check the “Relief” box in the top right-hand corner of Form 8962 and file that with your tax return.  You are not required to submit documentation of the abuse or abandonment with your tax return, but should keep any documentation for your records.