In this nationally representative sample of community-dwelling older adults who have diabetes, we found 3 classes of people, based on their comorbid conditions: people in class 1 (63% of the sample) had 2 or fewer comorbid conditions and were relatively healthy; people in class 2 and class 3 were sicker; they had 6 or more comorbid conditions, a higher 5-year death rate, more health care visits, and higher rates of insulin use, functional disability, and fair or poor self-rated health. This evidence concerns the gene INS and diabetes mellitus.