Col. Michael Burke, 21st Medical Group commander, passes a guidon to Lt. Col Brent Sonday during an assumption of command ceremony June 22, 2012. Sonday became the first commander of the 21st Medical Squadron on Schriever AFB. As part of the 21st Medical Group, the 21st MDS will provide seamless, patient-focused care to the Schriever beneficiary population, which includes diagnostic, preventative and treatment related health care services. (U.S. Air Force photo/Bill Evans)