It is poorly understood whether insurance type may be a major contributor to the underuse of oral anticoagulation (OAC) among patients with atrial fibrillation (AF), particularly for novel oral anticoagulants (NOACs). Methods We performed a retrospective cohort registry study of patients with insurance, AF, CHA2DS2-VASc ≥2, and at least one outpatient encounter recorded in the ACC NCDR's PINNACLE Registry between January 1, 2011 and December 31, 2014. We used hierarchical regression, adjusting for patient characteristics and clustering by physician, to evaluate the association of insurance type (Private, Military, Medicare, Medicaid, Other) with receipt of OAC (any OAC, warfarin, or NOAC). Results In 363,309 patients (age 75 ± 10; 48% female), we found a significant difference in proportions of OAC and NOAC prescription across insurance types (OAC: Military 53%, Private 53%, Medicare 52%, Other 41%, Medicaid 41%, P <.001; NOAC: Military 24%, Private 19%, Medicare 17%, Other 17%, Medicaid 8%, P <.001). After adjustment for patient characteristics and facility, private, Medicaid, and other insurance were independently associated with a lower odds of OAC prescription relative to Medicare, but military insured patients were not significantly different. After adjustment, military and private insurance were independently associated with a higher odds of NOAC prescription relative to Medicare, while Medicaid and other insurance were associated with a lower odds of NOAC prescription. Conclusions In a contemporary US AF population, there was significant variation of OAC prescription across insurance plans, with the highest among private and Medicare insured patients. These differences may indicate that insurance plan, and its associated pharmacy benefits, affect the pace of diffusion of new therapies.