As the population ages, both cancer and geriatrics’ conditions are increasing. Treating older adults with cancer requires thoughtful care management to avoid ageism on one hand and overtreatment on the other. In negotiating between these two alternatives, it is best to leave the staging of the cancer to the oncologist and the staging of the aging to the geriatrician. I present how geriatrics evaluation can best be incorporated in the care of older cancer patients. Geriatrics can contribute: 1) a screening evaluation of older adults to identify those needing further aging assessments; 2) an assessment of the likelihood of toxicities or complications from cancer treatment; 3) an evaluation of cognitive status for competence or capacity for consent; 4) monitoring of geriatrics-specific complications such as falls, delirium, or mobility problems; and 5) interventions to maintain functional independence during treatment.