MD and DC have tax reciprocity with regard to W-2 wages. If you are a full-year resident of DC and you work in MD, your W-2 wages are not subject to MD income tax. You need only file a DC tax return. For tax purposes, your MD earnings are considered DC income, and are taxable by DC. If you entered MD in the Other State Income section of Personal Info, change it to No Entry.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.