Yes, as a PA resident your income is 100% taxable by PA, regardless of where you earned it. So you must file a PA tax return.
Since PA and MD are reciprocal states for salary or wages, it is not necessary for you to file an MD tax return unless MD taxes were mistakenly withheld from your pay, or unless you had income from MD other than W-2 salary or wages.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
