UDC offers FREE speech therapy at it's speech and hearing center, GWU costs $50 a session. My son went to GWU for speech starting at 18 months, when he had delayed expressive and receptive language, language of a 9 month old, It was a huge blessing and he recovered.
Definitely contact your insurance and ask for a list of all in network providers. National Rehabilitation Center, Georgetown university and children's hospital all have centers and take most insurance.
Our speech therapist recommended the following books to help me work with our son at home in our normal daily life:
http://www.hanen.org/Guidebooks---DVDs/Parents/It-Takes-Two-to-Talk.aspx.
And
http://www.woodbinehouse.com/main.asp_Q_product_id_E_1-890627-48-8_A_.asp
It can all be a bit overwhelming, but I felt like the hassle of schlepping across town on the metro, paying out of pocket, filing insurance forms myself, re thinking about our interaction and how I talk to him to encourage verbal responses paid off in the end, when he was in kindergarten and having a problem with reading (there is a correlation between delayed language and difficultly learning to read) and his kindergarten teacher was shocked to learn that my (now) highly verbal and very articulate child had delayed language.
Hang in there.