I live in Va and just accepted a position in MD, do I pay taxes in MD or VA?

I live in VA and accepted a position in MD, which state to I pay taxes to?
Do I fill out a W4 for VA or MD

VA and MD have a reciprocal tax agreement which allows you to pay tax only to VA, even though you work in MD. You should contact your payroll department to ensure that they withhold VA taxes from your wages, and not MD taxes. You will have to sumbit Maryland form MW-507 to make this work.

Good to know, but if that does not happen, filing both state returns and claiming a tax credit on the Virginia return for taxes paid to Maryland will also work.