As you get older, your need for healthcare will increase -- and your costs will rise along with your demand for services. While you may assume Medicare will cover your healthcare expenditures, the truth is that Medicare isn't as comprehensive as most people think it is.

There are co-insurance costs and gaps in coverage that can force seniors to pay out of pocket for many services. Sometimes, these costs can be astronomical. If you require lots of costly prescriptions and you want a 90% chance of being able to pay all of your out-of-pocket healthcare costs, you may need to save $349,000 per couple, according to a new report from the Employee Benefit Research Institute.

Saving enough to cover your healthcare costs is vitally important to ensure that higher-than-expected healthcare bills don't derail your plans for a financially secure retirement. But costs can vary widely, so how much money do you actually need saved up to cover the costs of care?