Update of the 2005 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for abdominal aortic aneurysm (AAA). The USPSTF commissioned a systematic review that assessed the evidence on the benefits and harms of screening for AAA and strategies for managing small (3.0 to 5.4 cm) screen-detected AAAs. These recommendations apply to asymptomatic adults aged 50 years or older. The USPSTF recommends 1-time screening for AAA with ultrasonography in men aged 65 to 75 years who have ever smoked. (B recommendation). The USPSTF recommends that clinicians selectively offer screening for AAA in men aged 65 to 75 years who have never smoked. (C recommendation). The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for AAA in women aged 65 to 75 years who have ever smoked. (I statement). The USPSTF recommends against routine screening for AAA in women who have never smoked. (D recommendation).