The purposes of this article were to estimate construct validity for the FAMS (7), using the nonrecursive model that it was designed to test (5). We also wished to compare the applicability of both the model and the instrument to explaining family adaptation to nonmedical as well as medical stressors. Data from 570 respondents who were participating in three independent studies were used in these preliminary, cross-sectional analyses that were considered appropriate to accomplishing these goals. Results of a regression analysis used to test the hypothesis that mental-health resources would contribute to the explanation of mental-health outcomes indicated that a pileup of stressors, role inflexibility, rules prohibiting emotional expression, family income, and perceived severity of the stressor to which respondents referred contributed to the explanation of variance in negative family mental-health outcomes. Results of an analysis of covariance for the two samples in which respondents selected the stressor to which their responses referred supported the hypothesis that these findings are unrelated to whether a medical or nonmedical stressor was chosen. It was concluded that the results warrant use of both the model and the instrument in longitudinal studies of family adaptation to medical and nonmedical stressors.