Until relatively recently, most psychologists have had limited professional involvement with older adults. With the baby boomers starting to turn 65 years old in 2011, sheer numbers of older adults will continue to increase. About 1 in 5 older adults has a mental disorder, such as dementia. Their needs for mental and behavioral health services are not now adequately met, and the decade ahead will require an approximate doubling of the current level of psychologists' time with older adults. Public policy in the coming decade will face tensions between cost containment and facilitation of integrated models of care. Most older adults who access mental health services do so in primary care settings, where interdisciplinary, collaborative models of care have been found to be quite effective. To meet the needs of the aging population, psychologists need to increase awareness of competencies for geropsychology practice and knowledge regarding dementia diagnosis, screening, and services. Opportunities for psychological practice are anticipated to grow in primary care, dementia and family caregiving services, decision-making-capacity evaluation, and end-of-life care. Aging is an aspect of diversity that can be integrated into psychology education across levels of training. Policy advocacy for geropsychology clinical services, education, and research remains critical. Psychologists have much to offer an aging society. (Contains 1 table.)