I live in Maryland and work in DC, and my W-2 forms shows no DC taxes. But TurboTax says I need file a DC return. Why?

[ErnieS0]

You do not have to file a Washington D.C. return. 

Maryland and D.C. have reciprocity. A Maryland resident working in D.C. files and pays tax to Maryland only.

When you Live in One State and Work in Another

[SteamTrain]

....also, because of the tax reciprocity agreement...

IF only MD taxes were withheld, then on the My Info page, you Do Not indicate that you worked in another state (DC) during the year.  That's the setting that prompts the DC tax return....unless you did have some DC taxes withheld on some form (or own a rental property in DC).

Take out DC from the Other State Income section on the MyInfo page first, then go to the state tax return section and delete the DC form set (if you already started it)