Federal regulations require that routine bioassay programs be established for workers likely to receive internal radiation doses. Bioassay programs determine kinds, quantities, or concentrations, and, in some cases, locations of radioactive material in the body. The Department of Energy's (Department) bioassay programs consist of two parts. In-vivo (inside the body) measurements include activities like whole-body, lung, and thyroid counting. In-vitro (outside the body) monitoring, on the other hand, includes radiochemical analyses of workers’ urine and fecal samples. Our audit was limited to bioassay analyses of urine samples, which represent 98 percent of all in-vitro analyses. In Fiscal Year (FY) 1999, the Department performed about 69,500 bioassay analyses at the 7 sites reviewed at an estimated cost of $7.7 million. The objective of this audit was to determine whether the Department's contractors obtained bioassay analyses at the lowest prices available.