Retirement planning should include consideration of how frailty — or deteriorating mental or physical health — may impact security. Citing work by Christine Cigolle and Mary Beth Ofstedal, this story says that nearly a third of people age 65 and older suffer from some degree of frailty, which can spell unanticipated financial risk to a retirement plan. Several recommendations are made to lessen the risk of frailty and, more important, to lessen its impact.