The steepest declines in coverage have been in small businesses, which had been steadily dropping coverage before the law. The percentage of small employers offering health benefits decreased from 68 percent in 2010 to 56 percent in 2015, according to the annual Kaiser Family Foundation survey.

But those companies now seem less likely to exit than just a few years ago. In 2013, as many as a fifth of employers with fewer than 500 workers said they were likely to drop coverage in the next five years, compared with 7 percent today, according to a survey from Mercer, the benefits consultant.

Tracy Watts, a senior partner at Mercer, said the stabilization at small businesses was mostly a product of their health care costs staying the same or rising only modestly.

“That will keep you in the game,” Ms. Watts said.

The early tumult in the insurance marketplaces, including the troubled introduction of HealthCare.gov, the federally run insurance marketplace for the Affordable Care Act, also made dropping coverage less tenable, analysts said.

The law has resulted in more coverage for low-income people, as expected. But the unexpected exit by some of the start-up insurers has limited options on the marketplaces. And the plans on the exchanges remain less generous than those offered by many employers, with significantly higher deductibles and a significantly narrower choice of hospitals and networks.

Lowe’s, by comparison, said it has tried to keep employee costs low by contributing about 70 percent of the cost of the annual premiums. It offers plans with deductibles as low as $1,000, versus several thousand dollars for many of the exchange plans.

“The exchanges have been less of a disrupter than I expected,” said Thomas Buchmueller, a business professor at the University of Michigan.