A model is presented for classifying nursing home patients according to nursing resource use. The model is derived from a study of 558 Medicaid nursing home patients in 12 facilities in Virginia. Data were obtained from self-reports of nursing staff for care delivered over a 52-hour period. The measure of care time was validated through concurrent work sampling. Project staff also assessed the patients' health and functional status using a standardized instrument. Using AID analysis patients were classified into six groups that were homogeneous in their use of nursing resources. Patients were initially categorized by presence or absence of conditions requiring specialized care (e.g., nutritional intake problems, quadriplegia, wounds or lesions, coma, and physical rehabilitation potential). For the specialized care category, two groups were formed by presence or absence of a catheter/ostomy. In the nonspecialized care category, four groups were formed by ADL impairment score and assistance required in eating/feeding. Mean resource use for the highest group was nearly four times that of the lowest group. The model accounted for 53% of the variance in nursing resource use.