Retirees may need hundreds of thousands of dollars more than they plan for to cover health-care costs in retirement, according to data from the Employee Benefit Research Institute (EBRI). This comes after accounting for Medicare, the U.S. federal health insurance program for people 65 and older, which covers many services. A 65-year-old couple may need about $405,000 to cover expenses, based on a scenario that assumes a 90% chance of covering costs. This estimate reflects how much retirees may need to have saved to cover premiums, out-of-pocket costs and prescription drug spending over retirement. Experts suggest that retirees often underestimate how much they'll still pay out of pocket over time.