Ectopic pregnancy (EP) is a rare adverse outcome in which a fertilized egg implants and develops outside of the uterus. Life-threatening cases of EP among deployed U.S. service members have been described. During 2002- 2011, among active component females younger than 49, 1,245 EPs were diagnosed and treated as indicated by diagnostic and procedure codes recorded in electronic medical records. Annual numbers of EPs ranged from 91 to 151. During the period EP affected 0.64 percent of all pregnancies, with higher proportions among servicewomen in their 30s and of black, non-Hispanic race/ ethnicity. As compared with civilians, service members had the same percentage of pregnancies that were ectopic but had lower proportions of EPs that were treated medically (with methotrexate) rather than surgically.