OBJECTIVES: To examine characteristics of physicians who are early adopters of new expensive drugs METHODS: Retrospective analysis of pharmacy claims from 2006-2010 for 3 expensive diabetes drugs (exenatide,  saxagliptin, and sitagliptin) identified by medical directors and pharmacists at large health plan in Hawaii.  We examined how physician specialty and urban setting affected likelihood of being an early prescriber.  We calculated total paid costs and days supply by quarter for each physician.  We also examined whether same physicians tended to be early adopters of all drugs. RESULTS: Characteristics of early adopters differed by medication.  For saxagliptin, during first 2 quarters, 53% of prescriptions were made by internists, 30% by general/family practitioners, 17% by other specialists and <1% by endocrinologists.  This distribution stayed fairly stable over time.  In contrast, for exenatide, in first 2 quarters usage was highest for endocrinologists (28%), Medicaid providers (29%) or other specialists (25%).  By the end of 2010, however, most exenatide prescriptions were being made by internists or general/family practitioners. The trends for sitagliptin were similar to that of exenatide with endocrinologists (32%), Medicaid (34%) and other specialists (30%) being early adopters with a shift toward more prescriptions by primary care physicians. Early adopters tended to be in urban areas.  75% of physicians were early prescribers of one drugs, 25% were early prescribers of two drugs, and none were early prescribers of all three medications. CONCLUSIONS: Research of this nature may enable us to target intervention programs to promote cost-effective prescribing patterns.