Reciprocity rules in the DC Metro area. In the case of wage/ W2 income, you only file a tax return with the state that you live in, regardless of where you work (and the HQ of a company doesn't usually matter anyway)
In your case, you should have had Maryland taxes withheld from that job. And, you would not indicate DC inside of Turbo Tax at all, unless DC taxes were withheld in error.
http://otr.cfo.dc.gov/sites/default/files/dc/sites/otr/publication/attachments/2016%20D-40B%201.06.1...
You can use the form above (yourself or through Turbo Tax) to get back any DC taxes withheld in error.
If you only had Maryland taxes withheld, you are good to go! Just make sure you don't list DC on the Personal Info tab as "Other State Income".
