OBJECTIVES: To examine incidence, prevalence and mortality rates among opioid-dependent patients in the U.S. Medicare population. METHODS: A study was performed for the period from January 1, 2008 through December 31, 2012 to determine the prevalence, incidence and mortality rates among opioid-dependent patients (International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes 304.0x and 304.7x) in the U.S. Medicare population. Patients who had continuous fee-for-service Medicare health plan enrollment for the calendar year and at least 2 years prior were selected for the study. Age- and gender-adjusted opioid dependence prevalence and incidence rates were calculated via direct standardization to the U.S. population age ≥65 years in 2010 using gender-specific age groups. RESULTS: The annual adjusted prevalence of opioid-dependent patients increased from 0.06% in 2008 to 0.35% in 2012. Incidence rates increased from 0.06% in 2008 to 0.10% in 2012. Prevalence rates were higher among women than men every year during the study period. Patients age 65-69 years had the highest prevalence rates during 2008 (0.09%), 2009 (0.16%), 2010 (0.22%) and 2011 (0.32%). However, in 2012, patients who were age 70-74 years had the highest prevalence rates (0.43%). North American Natives had the highest prevalence of opioid dependence compared to all other races. The highest incidence of opioid dependence was observed in Nevada in 2008 (221.9 per 100,000 person-years) and 2012 (222.1 per 100,000 person-years). The 30-day and 1-year mortality rates decreased by 10.5% (3.8 to 3.4 per 1,000 person-years) and 25.4% (17.3 to 12.9 per 1,000 person-years), respectively, from 2008 to 2012. CONCLUSIONS: Opioid dependence incidence and prevalence decreased from 2008 to 2012; however, opioid dependence-related mortality rates increased.