Here's an even bigger reason to start saving for retirement -- immediately.

Many of us by now have been exposed to the dire reality of financing healthcare in retirement. For years, Fidelity has been releasing data on estimated retiree healthcare costs, and according to the most recent assessment, a 65-year-old couple retiring today can expect to spend $245,000 over the course of a 20-year retirement, not including nursing home or long-term care expenditures.

If you're thinking $245,000 sounds bad, here's some even worse news. There's new data out there suggesting Fidelity may actually be grossly underestimating healthcare costs in retirement. HealthView Services, a provider of healthcare cost-projection software for financial advisors and institutions, released its 2016 report on this very topic, and its data show the average healthy 65-year-old couple retiring this year is expected to spend $288,000 in lifetime healthcare costs. And while HealthView's numbers span a slightly longer timeframe than Fidelity's (all projections assume an average life expectancy of 87 for men and 89 for women), that $288,000 doesn't include typical out-of-pocket costs for services not covered by Medicare, like vision and dental care. When we add in those expenses, the total lifetime cost for a healthy 65-year-old couple today rises to $377,000.