Health care in retirement can come with a hefty price tag.

A new study looks at how much money a 65-year-old — who’s at the age of Medicare eligibility — would need to have set aside to secure a 50%, 75% or 90% chance of covering their health-care costs over the course of their retirement. Depending at least partly on a person’s coverage choices through Medicare, the amount could reach into the hundreds of thousands of dollars, the research shows.

“Health care is likely going to be a big expense for you in retirement,” said Paul Fronstin, director of health-benefits research at the Employee Benefit Research Institute and a co-author of the study.

“You don’t want to be shocked when you get to retirement and find this out, or discover that Medicare doesn’t cover everything,” Fronstin said.

The study assumes that the pot of money set aside at age 65 is invested and even as you make withdrawals to cover health-care costs, the account is earning 7.32% in interest and investment returns yearly. In other words, you could end up spending far more than the amounts in the study.

Here are the two common coverage scenarios that were analyzed. 

The first scenario involves pairing basic Medicare — Part A (hospital coverage) and Part B (outpatient care) — with a stand-alone Part D (prescription drug coverage) plan and a so-called Medigap policy, both of which are offered by private insurance companies.

Medigap covers some or most of the cost-sharing — i.e., deductibles, copays or coinsurance — that come with basic Medicare. Plans are standardized across most states — they are simply designated A, B, C, D, F, G, K, L, M and N and each lettered plan differs in what is covered. The standardization means the benefits are generally the same regardless of where you live or which insurance carrier is offering, say, Plan G or Plan N.

While Medigap coverage means fewer out-of-pocket expenses — and therefore might be a more predictable budget item — the premiums can be pricey, depending on where you live and the specifics of the policy. And over time, those monthly payments add up.

This shows up in the study: A 65-year-old man enrolled in a Medigap Plan G with average monthly premiums — $204 is used for the calculation — would need to have saved $96,000 to have a 50% chance of having enough money to cover premiums and median prescription drug expenditures, the analysis finds.

A woman of the same age and with the same coverage choices would need to have $116,000 for the same 50% chance of having enough money. (The higher amount is due to women generally living longer than men.)

For a 75% chance, the same man and woman would need to have saved $137,000 and $159,000, respectively. And for a 90% chance, those amounts would be $166,000 and $197,000.

Representing an extreme case, a couple with high prescription drug expenses would need to have saved $383,000 to have a 90% chance of having enough to cover their health-care costs.

The second coverage scenario analyzed in the study involves a Medicare Advantage Plan, which delivers Parts A and B, and typically Part D, as well extras like dental and vision. Of Medicare’s 64.5 million beneficiaries, 29.1 million are enrolled in Advantage Plans and that number is expected to continue growing. 

While many Advantage Plans have no premium, they do have their own deductibles, copays or coinsurance and out-of-pocket maximums that vary from plan to plan. Additionally, the Part D coverage of each plan can vary in terms of premiums, deductibles and copays, as well as which prescription drugs are covered. (This is the same case as the stand-alone Part D plans.)

Although there is a lot of variation among individuals arising from how often they use health-care services and their overall health, enrollees in Advantage Plans generally would need lower savings targets, the study shows.

A 65-year-old man with median health-care expenditures would need $56,000 set aside to have a 50% chance of meeting his health-care spending needs, and a woman in that situation would need $67,000, according to the study. For a 75% chance, the man would need $79,000 set aside, and the woman, $92,000. And for a 90% chance, those respective amounts are $96,000 and $113,000.

“With Advantage plans, your primary spending will be for services as you go, as opposed to Medigap where you pay higher premiums for less cost-sharing on the back end,” said Danielle Roberts, co-founder of insurance firm Boomer Benefits and author of the book “10 Costly Medicare Mistakes You Can’t Afford to Make.”

Here’s another big difference between the two scenarios: Advantage Plans often require you to use their network of providers — doctors, hospitals, pharmacies and the like — and that’s not the case if you have basic Medicare only, with or without Medigap.

Regardless, it’s important to consider your own health-care needs before assuming an Advantage Plan would be less expensive, Roberts said.

“Sometimes people choose a Medicare Advantage Plan for a low premium only to find out they’ll shell out hundreds of dollars each year for their Part B medications [those administered in a doctor’s office] or durable medical equipment,” Roberts said. “In this case, Medigap can actually be more cost-effective.”

However, she said, it’s also important to remember that Medigap premiums do go up annually, generally speaking.

“If paying the premium is a stretch for you at age 65, you may not be able to keep up with the premiums over the years as increases occur,” Roberts said. “This is one of the reasons we see so many people switching to Medicare Advantage Plans.”