Increasingly, adults are living to an advanced age. While many enjoy good health, nearly 50% of adults older than 65 years have 3 or more chronic medical conditions. Furthermore, within any age-sex cohort, older adults exhibit widely heterogeneous health status--ranging from robust to frail. This heterogeneity and individual medical complexity makes care for older patients particularly challenging and requires both careful medical judgment and a clear understanding of the patient's personal values and goals. Most current health care guidelines are disease-specific and do not address this complexity and heterogeneity, thus limiting their utility for guiding physicians in the care of older adult patients. The "Guidelines for Improving the Care of Older Persons With Diabetes Mellitus" are the first guidelines to specifically address this complexity and provide guidance to physicians who must prioritize therapies and goals for older adults with diabetes, comorbid medical conditions, and geriatric syndromes. By providing a rationale for prioritizing recommendations and the inclusion of geriatric syndromes that impact the patient's overall health and diabetic care, these guidelines may serve as a model for the development of other guidelines targeting older adults with complex health status.