Fidelity also had a look at long-term care costs, expected to hit 7 out of every 10 Americans who reach the age of 65 in the next five years. Long-term care costs are not covered by Medicare as a general rule; instead, those in need of long-term care must usually rely either on insurance or Medicaid — depending on their financial circumstances.

In its estimate of long-term care cost, Fidelity said that that 65-year-old couple would need an additional $130,000, on top of their savings for retiree medical expenses, to insure against long-term care expenses. But that couple had better be healthy; the estimate was based on the assumption that the couple is in a good health and purchases a policy with an $8,000 monthly maximum benefit, with three years of benefits, and an inflation adjuster of 3 percent per year.

One way employees can stretch their health care dollars, Fidelity said, is through a health savings account.

Fidelity itself provides Health Savings Accounts for nearly a half million workers; it said that the number of Health Savings Accounts in the United States rose to 16.7 million in 2015, which was an increase of 22 percent from the previous year. Health Savings Accounts provide a triple-tax advantage to account holders to save for qualified medical expenses, and many people are choosing to invest their Health Savings Account money with an eye toward growth, so that it goes farther on their medical expenses in retirement.