The authors examined global charges (incorporating both technical and professional components) and global reimbursement allowances for all radiographic and ultrasound (US) examinations performed on Pennsylvania Blue Shield subscribers in the Lehigh Valley area of Pennsylvania during 1990. Data for radiologists and nonradiologists were compared with respect to all procedure codes for which at least 25 claims were submitted, yielding a sample of 40,619 radiographic examinations (54 procedure codes) and 9,761 US examinations (11 procedure codes). Radiologists' mean charges were higher than those of nonradiologists for 38 of the 54 radiographic codes. However, nonradiologists received higher mean reimbursement allowances for 39 of the 54 codes. Among the 11 US codes, nonradiologists' mean charges were higher for 10 and they received higher mean reimbursement allowances for seven. The averages of the mean reimbursement allowances for individual codes were higher for nonradiologists in both the radiographic and US categories. Pennsylvania Blue Shield has begun steps to eliminate disparities in reimbursements to providers who submit claims for imaging examinations.