American incomes have barely changed over the past 20 years on an inflation-adjusted basis, and that's due in large part to the exploding costs of health coverage.

The big picture: More people are plunging deeper into debt as the costs of housing, college and consumer goods greatly outgrow their paychecks. And those paychecks have been stagnant because employers are shoveling more money toward workers' health insurance.

Between the lines: Employers consider a block of compensation for every employee. Health insurance, which is exempt from taxes, has eaten up a lot more of that block over time.

In 1999, the average health insurance coverage for a family consumed 14% of the average household income, according to inflation-adjusted figures from the Census Bureau and the Kaiser Family Foundation.

By 2017, family coverage absorbed more than double that amount, to about 31% of take-home pay.

Health insurance has hovered consistently around 31% of household income since 2012, as companies shifted their employees to plans that had steady premiums but higher deductibles and out-of-pocket costs — a strategy that has largely backfired.

The bottom line: Controlling the costs of employer coverage means pushing back against the health care system, and more employers are doing this as they reach breaking points.

Go deeper: