IMPORTANCE Child maltreatment and other adverse childhood experiences, especially when recent and ongoing, affect adolescent health. Efforts to intervene and prevent adverse childhood exposures should begin early in life but continue throughout childhood and adolescence. OBJECTIVES To examine the relationship between previous adverse childhood experiences and somatic concerns and health problems in early adolescence, as well as the role of the timing of adverse exposures. DESIGN Prospective analysis of the Longitudinal Studies of Child Abuse and Neglect interview and questionnaire data when target children were 4, 6, 8, 12, and 14 years old. SETTING Children with reported or at risk for maltreatment in the South, East, Midwest, Northwest, and Southwest United States Longitudinal Studies of Child Abuse and Neglect sites. PARTICIPANTS A total of 933 children who completed an interview at age 14 years, including health outcomes. EXPOSURES Eight categories of adversity (psychological maltreatment, physical abuse, sexual abuse, neglect, caregiver's substance use/alcohol abuse, caregiver's depressive symptoms, caregiver treated violently, and criminal behavior in the household) experienced during the first 6 years of life, the second 6 years of life, the most recent 2 years, and overall adversity. MAIN OUTCOMES AND MEASURES Child health problems including poor health, illness requiring a doctor, somatic concerns, and any health problem at age 14 years. RESULTS More than 90% of the youth had experienced an adverse childhood event by age 14 years. There was a graded relationship between adverse childhood exposures and any health problem, while 2 and 3 or more adverse exposures were associated with somatic concerns. Recent adversity appeared to uniquely predict poor health, somatic concerns, and any health problem. CONCLUSIONS AND RELEVANCE Childhood adversities, particularly recent adversities, already show an impact on health outcomes by early adolescence. Increased efforts to prevent and mitigate these experiences may improve the health outcome for adolescents and adults.