Study purpose was to revise and examine the validity of the Medication Adherence Self-Efficacy Scale (MASES) in an independent sample of 168 hypertensive African Americans: mean age 54 years (SD = 12.36); 86% female; 76% high school education or greater. Participants provided demographic information; completed the MASES, self-report and electronic measures of medication adherence at baseline and three months. Confirmatory (CFA), exploratory (EFA) factor analyses, and classical test theory (CTT) analyses suggested that MASES is uni-dimensional and internally reliable. Item response theory (IRT) analyses led to a revised 13-item version of the scale: MASES-R. EFA, CTT, and IRT results provide a foundation of support for MASES-R reliability and validity for African Americans with hypertension. Research examining MASES-R psychometric properties in other ethnic groups will improve generalizability of findings and utility of the scale across groups. The MASES-R is brief, quick to administer, and can capture useful data on adherence self-efficacy.