Certain retirement expenses, like transportation, utilities, and communication services, are fairly predictable. But if there's one senior expense that can be difficult to nail down, it's healthcare. There are so many variables that go into that equation, especially the evolving state of one's health.

But there are estimates out there as to what healthcare in retirement will cost, and being aware of them can help seniors come up with a plan.

Recently, Fidelity threw out an estimate of $285,000 for a 65-year-old couple retiring this year. That figure is meant to encompass out-of-pocket costs such as Medicare premiums, deductibles, and co-pays.

Clearly, that's a pretty big number. But if you're worried about $285,000, here's worse news: According to consulting firm Milliman, the average healthy 65-year-old couple retiring in 2019 will spend $369,000 on healthcare in retirement. That's a pretty substantial jump from Fidelity's number, and it's based on Medicare costs coupled with projected healthcare inflation rates. It's also meant to cover a couple made up of one male and one female with life spans of 87 and 89, respectively.

Doctor smiling while talking to older male

Image source: Getty Images.

To be fair, those ages are a bit higher than the life expectancies the Social Security Administration assigns to seniors -- 84 for men and 86.5 for women among those reaching age 65 today. Whichever you believe, the message is clear: Workers today need to save a substantial sum to cover healthcare in retirement. If they don't, they'll inevitably wind up struggling financially.

Saving to afford senior healthcare

It's almost impossible to land on a single correct number that'll encompass your total healthcare spending in retirement. Factors such as your health, your Medicare plan, the supplemental insurance you choose (if any), and the prescriptions you take will heavily influence your healthcare bills. But you can use the aforementioned number as both an estimate and a wake-up call, and save accordingly.

First, you can boost your savings in your IRA or 401(k) to give yourself more income during your later years to use for any purpose, healthcare included. If you're 50 or older, annual contributions max out at $7,000 and $25,000, respectively, for these plans. If you're younger, you're limited to $6,000 a year in an IRA and $19,000 in a 401(k), but you also have a longer savings window between now and retirement, so if you're nowhere close to maxing out at present, aim to ramp it up.

Second, if you're eligible to participate in a health savings account, or HSA, doing so is a good way to set aside funds that will be earmarked for healthcare expenses down the line. HSAs are similar to flexible spending accounts (FSAs). But while FSA balances must be used up from year to year, HSA balances can carry over and grow via investments. In fact, the point of an HSA is to put in more money than you need for medical care at present so there are funds left over to invest and have on hand for retirement.

You can qualify for an HSA if you have a high-deductible health insurance plan, defined as $1,350 for single coverage, or $2,700 for family coverage. The annual contribution limits for HSAs are $3,500 for individual coverage, or $7,000 for family coverage, and if you're at least 55, you get an extra $1,000 catch-up on top of whatever limit applies to you.

The best part of HSAs: They're funded with pre-tax dollars, but they also get to grow tax-free, and withdrawals can be taken tax-free as long as they're used to pay for qualified medical expenses.

Estimating your healthcare costs in retirement isn't easy, even with different projections from reputable sources. The best you can do, therefore, is save as much as you can so that when those medical bills eventually start rolling in, you'll have the money to pay for them.