Even if your employer offers you health insurance at work, chances are you're shelling out more money for medical care.

Last year, employers spent an average of $15,159 in premiums to cover a family of four, according to an analysis from the Kaiser Family Foundation. In all, that's an increase of 51% from a decade ago.

Things haven't become any more affordable for workers, either.

The average family of four paid a total of $7,726 in 2018, according to the foundation. That's an increase of 67% from 10 years ago.

Of that amount, families paid $4,706 in premium contributions for coverage at work, plus $3,020 in cost-sharing — that is, deductibles, coinsurance and copayments.

The cost of coverage has even outpaced wage growth, which has gone up by 26% over the last decade.

Bear in mind, employers still shoulder a large share of premiums. Employees also have the advantage of paying premiums on a pretax basis, as opposed to buying coverage elsewhere with after-tax dollars.

In contrast, on the private market, a family of four with an annual household income of $80,000 would pay $7,888 per year in premiums for a silver plan purchased through the health insurance marketplace — provided they are eligible for a premium tax credit of $9,961 per year, according to Kaiser.

Without the credit, the plan would cost close to $18,000 per year.

"Insurance companies get a lot of heat for raising deductibles and premiums," said Cynthia Cox, vice president at the Kaiser Family Foundation.

"But if you look at what's driving health-care costs year to year, it's the price of health care: the cost of doctor's visit, the cost of a hospital stay," she added. "That's really what's making those premiums and deductibles go up each year."