I don’t have any doctor recos for you, but if you have the ability to switch your insurance, I highly recommend Kaiser Permanente. I’ve had them for an HMO for over a decade now and am very happy. Their center next to Union Station is really convenient (don’t even have to go outside to get there from the Red Line…just walk through Union Station and another walkway to get there). Most services can be performed right there. Some specialty stuff you may have to go to Washington Hospital Center for (accessible by bus).