OBJECTIVES: To examine geographic variation associated with atrial fibrillation (AF) prevalence in the U.S. veteran population as well as the distribution of AF, stratified by age. METHODS: This study analyzed a patient sample in the Veterans Health Administration (VHA) Medical SAS datasets (October 1, 2005 - May 31, 2012). All patients diagnosed with AF in 2011 were identified using International Classification of Disease 9th Revision Clinical Modification (ICD-9-CM) diagnosis code 427.31. AF prevalence, stratified by U.S. state and age group, was determined. Descriptive statistical analyses were performed using SAS v9.3 software. RESULTS: A total of 1,255,349 veteran patients were diagnosed with AF in 2011. Prevalence results showed an increase as patient age rose (age 18-25: 0.02%, 16-34: 0.05%, 35-54: 0.39%, 55-64: 2.0%, 65+: 6.06%). Prevalence also varied by state. AF was most prevalent in Vermont (5.05%), Connecticut (4.75%), Massachusetts (4.64%) and Utah (4.62%). AF had low prevalence in Hawaii (1.99%), Colorado (1.96%), Guam (1.69%) and Washington D.C. (1.62%). All states throughout the United States showed disease prevalence above 1.5%, but none had a rate greater than 5.5%. Only Vermont was observed with prevalence slightly greater than 5.0%. CONCLUSIONS: U.S. veterans living in Utah and in the Northeastern U.S. region (including Vermont, Massachusetts, and Connecticut) had high regional prevalence of AF in 2011. Geographic variation in high risk areas can help identify important geographically connected prognostic factors, aid in targeted intervention strategies, and generate hypotheses regarding underlying causes of AF in the United States and associated territories.