The predictive and incremental validity of the New Medical College Admission Test (New MCAT) Science Problems Subtest was examined with a sample of over 165 medical students. Criterion measures were National Board of Medical Examiners (NBME) Part I (basic science) and Part II (clinical science) performance. The Science Problems subscore is derived from a subset of the same items found on the Biology, Chemistry, and Physics subtests, creating nonindependence. Results of incremental validity analyses and of all possible subsets regression analyses using Mallow's Cp criterion raise questions concerning the practical utility of the Science Problems subtest in prediction equations to make admission decisions. Cross-validation analyses supported the inclusion of the Biology subtest in prediction models of both NBME Parts I and II, and of the Chemistry subtest for NBME Part I. (Author)