Functional health outcomes resulting from intensive insulin regimens may differ depending upon the age of the diabetic patient. This study tested the hypothesis that health functioning is poorer for younger insulin-dependent diabetic (IDDM) patients following a change to the insulin infusion pump regimen, with progressive improvements occurring in functional health status at higher age levels. Thirty IDDM patients aged 10-47 years were administered health status instruments prior to changing to the new regimen, and again six months later. The instruments assessed physical, cognitive, psychological, and social health functioning. When compared at six months to an age-matched control group on conventional insulin therapy, declines in social activities were found for younger insulin pump patients, with improvements occurring linearly as age increased. Lower performance levels were also found for the younger patients in Conceptual Quotient (CQ), an indicator of cognitive functional status, with progressive improvements with age through the early 30s. However, corresponding declines in function occurred at the oldest age levels. Adaptation to an intensive diabetes regimen appears to be more difficult at younger and older age levels.