Here's a tough pill to swallow: A new AARP report reveals that the average American aged 65 and over spent nearly one-fifth of his annual income - roughly $2,400 - on health care last year. That sizeable chunk includes out-of-pocket expenses not covered by Medicare, as well as Medicare premiums and deductibles. After premium payments, prescription drugs are the single largest expense for seniors, accounting for 17 percent of total spending. In fact, seniors shell out as much for prescription drugs as they do for physician care, vision services, and medical supplies combined. The study also shows that one out of four elderly Medicare beneficiaries faces more than $3,000 in out-of-pocket expenses for health care a year. Even more grim, AARP's figures do not include the hefty costs associated with home health care and long-term nursing care.