Purpose. This study assesses the extent to which medical care for older adults is consistent with systematic quality standards. Previous studies find large variation in the quality of medical care and few studies identify factors associated with this variation. Methods. Using the three domains from the Donabedian model, structure, process and outcome, we assess what factors are related to one measure of quality: medical service fit. Service fit is measured as the proportion of medical services received to the medical services needed for a specific medical condition. We focused on 110 older adults who had medical conditions among 199 hospitalized depressed elders participating in a study of post-acute care. We assessed current medical conditions through the CIRS-G. This study focused on 14 common medical conditions in the sample. The range of comorbid medical conditions was one to four conditions per participant. A nurse practitioner developed guidelines to assess which medical services were needed for each medical condition. We reviewed medical service records six month prior to and six months after hospitalization to determine what services were received. Other variables measured included demographics, patient functioning, and adequacy of care from family caregivers. To identify factors related to medical service fit, we used generalized estimating equations. Results. Among 14 medical conditions, the patents with atrial fibrillation, Parkinson, congestive heart failure, low back pain, and cancer had the highest level of service fit (the proportion of medical services received to medical services needed was 80 percent). Whereas the patients with osteoporosis received the poorest service fit at 28 percent. On average, there was 70 percent service fit. One quarter of patients had less than 50 percent service fit (that is, only half of the services indicated by the medical condition were received). In addition, we found that process factors significantly affected service fit, in that those who had more visits to a medical professional had better medical service fit. In contrast, the use of emergency room was negatively related to service fit. Worse psychosocial functioning and poor cognitive impairment increased medical service fit. Those covered by Medigap insurance received better service fit. Adequacy of informal care was negatively related to medical service fit. Implication. In light of the large variation in the quality of medical care by medical conditions, we suggest that patients with certain conditions be targeted for closer follow-up in regards to medical care. Additionally, we found that appropriate medical care processes (like office visits versus ER visits) can enhance the quality of medical care. Although it is understandable that patients with worse psychosocial functioning and cognitive impairment are more likely to receive services in response to higher needs, questions about preventative care arise. This study suggests that adequate care from family members does not translate into getting needed medical services. Discharge planners can not assume that families have sufficient knowledge about patients' medical conditions and needed medical services. Increased attention should be paid to the role of informal caregiving in the delivery of medical services to older adults.