I used to live in the area up until this June.
There are several that I used to go to. There was a group that met at GWU once a week for group therapy. I don't know if they are still doing it but when I was in the area it was a good resource for me.
In addition as an actual support group I went to MAGIC. MAGIC stands for Metro Area Gender Identity Connection of Washington DC and you can find more information at
http://www.magicdc.org/There was also a really good one at Baltimore Maryland but sadly I can't remember the name of it. You might be able to find it by the general location though.
