It's time to pick a health plan. Make sure you run the numbers.

While the cost of job-based health insurance is moderating from earlier punishing increases, premiums are now a burden for many workers, health experts say. They recommend that employees review their options during this year's open-enrollment period to make sure they're not overlooking some cost savings.

Open enrollment, a window of time when employees select health coverage and other benefits for the coming year, is underway — or will be soon — at many workplaces.

Workers may assume that plan choices are the same as last year and pay scant attention. But that is not always the case. So employees should make time to review plans, said Tracy Watts, a senior partner and national leader for health policy at benefits firm Mercer.

"They need to do their homework," Watts said.

A survey from the Kaiser Family Foundation found that the average annual family premium increased 5% in 2019 and is now nearly $21,000, with workers paying $6,015 and employers the rest. The survey included more than 2,000 employers.

And the National Business Group on Health, which surveys large employers, expects the total cost of health benefits to rise 5% next year.

Adding to the cost are higher deductibles — what workers must pay for their medical care before their insurance covers it. The average single deductible is now $1,655, double what it was a decade ago, Kaiser found.

Employers said they typically added a "preferred provider" plan, or PPO, which allows workers to seek care from doctors in a network for a lower fee. Such plans often have higher premiums but lower deductibles.

"Employers are reintroducing choice," said Brian Marcotte, chief executive of the National Business Group on Health, which surveyed nearly 150 large employers.

What can employees do to manage their health costs?

Watts said workers should compare the plans that their employer offered and do the math: Take the total annual premium and deduct any employer payment to get the basic cost of each plan. (Many employers now offer online comparison tools.)

"People are often scared by big deductibles," she said. But high-deductible plans usually carry lower premiums and may come with an employer contribution — often to a special tax-free health savings account — which may make them less costly than a PPO plan.

Opting for a higher deductible and betting on staying healthy may be risky, however, if the family lacks funds to cover the deductible and pay for care, should the need arise.

The problem is that some medical needs are unpredictable. "No one says, 'I'm planning to get cancer next year,' " said Caitlin Donovan, a spokeswoman for the National Patient Advocate Foundation, a nonprofit group. Still, Donovan said, workers should at least try to estimate what they know they will spend money on before selecting a plan, such as prescriptions they take regularly or treatments they expect to schedule.

"Gamble with what you know," she said.

Check whether your plan will still cover your specific prescriptions and whether your doctor and hospital will remain in your covered network — where costs are lower — for the coming year and call to verify it. "Online directories are notorious for being inaccurate," Donovan said.

Also, if you are married, consider whether a spouse's health plan may be less costly, she said.

Another money-saving option to consider: Many employers will offer a premium discount, or contribute extra money to a health savings account, if workers agree to take a health assessment or screening. The idea is that identifying factors like smoking or high blood sugar can help people get treatment and avoid developing health problems that are more serious and costly to treat.