As a resident of NY, ALL your income is taxable by NY, regardless of where you earn it. Thus you MUST file an NY tax return.
If you actually (physically) perform any of your work in MD, then that portion of your income is also taxable by MD, and you must file a non-resident MD return in addition to your NY return.
If you never physically work in MD, you need file only the NY return.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
