Resident of VA with rental property in MD

State reciprocity is an agreement between two state in regards to income tax withholding on wages.  If you live in a state with a state reciprocity agreement with another state, then your nonresident state where you work would not withhold state taxes for the nonresident state.  Please see what is a state reciprocal agreement for more details.

As far as your original question on the Maryland rental income, you will need to review the questions in the state interview section for Maryland to ensure the rental income is the only thing being reported.  For example, in this sample Maryland state interview screen titled "Non-Maryland Income Allocation," the instructions are to enter the non-Maryland amount in the column while entering a zero for any amounts that are strictly from Maryland.

See this excerpt from Maryland for the filing requirements for nonresidents.

Please also see how do I file a nonresident state return for more areas of input that need to be completed within TurboTax.