I work in DC, but live in VA. My W2 shows I've been paying income tax to DC. Is this wrong? I know the two have reciprocity, but would I need to file for both states?

[IreneS · Accepted solution]

Yes - You should only have VA taxes withheld from your paycheck.

Yes - For 2018 you need to file:

• D-40B, Nonresident Request for Refund to get back any DC taxes that were withheld from your paycheck in error.
• VA  760 - Resident tax return reporting all your income since you are a VA resident.

For the future, you should ONLY be filing a VA return and NOT a DC return (unless you've already had DC taxes withheld already for 2019).

DC and VA have a reciprocity agreement--an agreement between two states that allows residents of one state to request exemption from tax withholding in the other (reciprocal) state. Since you live in VA, VA taxes should be withheld from your income. 

IMPORTANT:
File exemption form D-4A with your employer so that DC taxes won't be taken out in the future (just VA taxes). This will save you the trouble of having to file multiple state returns.