National VA Claims Assistant Office / Office Of Case Management. 202-273-7453 Source: 2014 Functional Organization Manual - v2.0a Description of Organization Structure, Missions, Functions, Tasks, and Authorities OFFICE OF COMMUNICATIONS AND CASE MANAGEMENT (20A3) Overview The Office of Communications and Case Management has overall responsibility for all activities related to resolving and responding to inquiries from Veterans that have reached the level of the SECVA and the USB.