Analyses of a nationally representative sample who completed a list recall task (weighted n = 6,446) and 2 mental status tasks (weighted n = 6,646) were conducted to determine whether specific medical conditions such as high blood pressure and diabetes as well as general health ratings predict cognitive performance in adults aged 70 to 103. Presence of stroke and poorer health ratings predicted poorer performance on the 3 tasks. Presence of diabetes predicted poorer performance on recall and 1 mental status task. Age interacted with medical conditions including high blood pressure and diabetes in predicting mental status, with condition-related deficits confined to the younger end of the age continuum. Global health ratings interacted with age, with poorer ratings asociated with worse mental status in the younger participants. Findings suggest that stroke and diabetes are associated with cognitive deficits. Some deficits are more pronounced in younger old adults with high blood pressure and poorer health ratings.