Measuring the interrelationship of personality and socioeconomic status (SES) over the adult life span is crucial in assessing how—or if—personality traits are involved in SES health differentials. Using data from Midlife in the United States cohort members of working age throughout a 16- to 17-year period, we studied the reciprocal relationship between personality traits and SES. Results indicated that standing on socioeconomic indicators was heavily shaped by both family of origin SES and education, with small positive associations of Openness and Conscientiousness and negative associations of Neuroticism and Agreeableness with SES indicators at subsequent waves. Results revealed small associations between socioeconomic factors and future Neuroticism, Conscientiousness, and Openness. Continuity in SES and personality dwarfed reciprocal influences. Findings suggest that any major selection effects of personality on SES occur prior to midlife, and that family of origin SES and education are common links to both adult SES and personality.