Objectives: To (1) identify adolescent and adult clinical preventive services guidelines relevant to the young adult age group; (2) review, compare, and synthesize these guidelines, with emphasis on the extent to which professional guidelines are consistent with evidence-based guidelines developed by the US Preventive Services Task Force; and (3) recommend the next steps in the establishment and integration of preventive care guidelines for young adults. Design: Nonexperimental: an Internet search was conducted to identify relevant preventive care guidelines for the young adult group. Setting: The search included federal agencies and professional organizations that focus on health areas linked to the care of young adults or that provide health care to adolescents and young adults. Participants: National organizations, federal agencies, health professional associations, and medical societies. Main Outcome Measures: Preventive services guidelines for adolescents and adults that intersect with the age range of 18 to 26 years. Results: When the ages of 18 to 26 years are carved out of established professional guidelines across specialty groups, there is a broad number of recommendations, with many supported by sufficient evidence to receive a US Preventive Services Task Force grade of A or B that can inform the care of young adults. Conclusions: We recommend the establishment of young adult preventive health guidelines that reflect the current evidence-based recommendations that overlap with the young adult age group; we suggest clinician and health care system supports to facilitate the delivery of preventive services to young adults; and we emphasize prioritizing research in prevention areas in which sufficient evidence does not exist.