Twenty-five years of experience with the Mayo Clinic computerized system for the Minnesota Multiphasic Personality Inventory (MMPI) have accrued since Swenson , Rome, and their colleagues proposed this innovation in 1959. Although it is the most respected, widely used, and thoroughly researched objective personality-assessment instrument that has been developed to date, the MMPI is aging. Work on the MMPI began in 1937, and the original normative base was established in the late 1930s and early 1940s . To develop new norms, we selected a random sample of 1,408 subjects, not under care for any physically or mentally handicapping condition and ranging in age from 18 through 99 years, from parts of Iowa, Wisconsin, and Minnesota in a 50-mile radius surrounding Rochester, Minnesota. MMPI responses obtained from this sample were used to develop normalized T-score tables for specific age ranges, and for adults in general, for the 13 basic scales of the MMPI.