It hasn't been announced yet. Typically the information for the Healthcon Regional Conferences will come out as the Healthcon National Conference gets closer.
You can keep an eye out for details on the AAPC website on the Conferences link - there's some very general information about DC there now, and more should be added as it becomes available: https://www.aapc.com/resources/events.aspx
Because if they've blocked rooms for the conference, there is a logical assumption you only need thru Tuesday night and will check out Wednesday morning to depart after conference ends? I've had this happen in the past and just called and spoke to someone to make the reservation or made a separate reservation for the remaining night.