The Tufts Health Plan Foundation announced last week that it will accept proposal letters for grants to support nonprofit healthy aging programs starting Monday. The proposals should focus on one of three grant topics: health and wellness, including issues like chronic disease management, exercise and nutrition, and mobility in older adults; purposeful engagement, which helps seniors become involved in their community through volunteer work and caregiver support; and empowerment, which aims to provide access to information so that older adults can learn about transportation, programs, and services in their communities. Last year, the foundation, which is headquartered at 705 Mount Auburn St., gave $2.8 million to 77 organizations in Massachusetts and Rhode Island, including four Watertown-based nonprofits: the regional chapter of the Alzheimer’s Association; Perkins School for the Blind; Springwell Inc.; and Watertown Community Foundation. The submission deadline is May 1 at 4 p.m.; finalists will be asked to submit a detailed plan by June 21. For more information on applying for the grants, visit the organization’s website, www.tuftshealthplanfoundation.org.