Veterans health care VA uses a projection model to develop most of its health care budget estimate to inform the Presidents budget request

"Funding for the Department of Veterans Affairs' (VA) health care is determined by Congress in the annual appropriations process. Prior to this process, VA develops a budget estimate of the resources needed to provide health care services to eligible veterans. The Veterans Health Care Budget Reform and Transparency Act of 2009 requires GAO to assess whether the funding requested for VA health care in the President's budget requests submitted to Congress in 2011, 2012, and 2013 is consistent with VA's estimates of the resources needed to provide health care services. In anticipation of these future studies, GAO was asked to obtain information on how VA prepares its health care budget estimate. In this report, GAO describes (1) how VA develops its health care budget estimate, and (2) how VA's health care budget estimate is used in the President's budget request to Congress. To conduct this work, GAO reviewed VA documents on the methods, data, and assumptions used to develop VA's health care budget estimate that informed the President's budget request for fiscal year 2011 and request for advance appropriations for fiscal year 2012. GAO also interviewed VA officials responsible for developing this estimate and staff from the Office of Management and Budget (OMB), which is responsible for overseeing..."