DO I HAVE TO FILE?
This booklet and forms are for residents of Maryland. In general, you must file a Maryland return if you are or were a resident of Maryland AND you are required to file a federal return. Information in this section will allow you to determine if you must file a return and pay taxes as a resident of Maryland. If you are not a resident but had Maryland tax withheld or had income from sources in Maryland, you must use Form 505 or 515, Nonresident Tax return.
Maryland Instructions