Unfortunately, there's not much in the way of specialized training available, particularly gerontology training that is specific to MFT. Some programs offer gerontology certificates or even full gerontology degrees, but usually in the context of a clinical psychology program.
There is surely a need for more. By 2030, more than 20% of the population will be over age 65. And they have needs that MFTs are well-suited to address:
[T]here are unique mental health and family issues among the elderly that require specific knowledge and training. For example, health problems, many of them being chronic, are common among the elderly. Thus, differentiating health issues from somatic symptoms commonly associated with depression becomes crucial[...] In addition, therapists need to know how to deal with unique family dynamics associated with older family members, such as widowhood, caregiving, and decisions about end-of-life care for a loved one (Yorgason, Miller, & White, 2009, p. 29, emphasis added).AAMFT's Family Therapy Magazine has done an outstanding job covering aging issues, with special sections on "Our Aging Selves" (November/December 2002), "Perspectives on Death & Dying" (March/April 2005), and "Retirement" (January/February 2007). There is not a shortage of information available. Possibly the most interesting piece of the new AJFT study is that the MFTs who work with older populations generally believe they got adequate training to do so, but they hunger for more. Who will answer the call?