The Medicare program turned 50 in 2015 and currently provides healthcare benefits for more than 50 million Americans.And while Medicare is how millions of retirees pay for healthcare, it's a complicated system with multiple parts, and it doesn't pay for everything. 

An old Carole King song captures the emotional value of having a friend. New research from the Stanford Center on Longevity confirms it, saying that social engagement promotes physical and mental health, while social isolation costs people both personal and medical problems. According to the study, "socially isolated individuals face health risks comparable to those of smokers."