The national picture could be even worse. This analysis looks only at states that have publicly released all insurance filings for next year, and some of those states have the most stable markets. In many of the remaining 32 states with the health exchange plans, insurers have been requesting large price increases, and lower-cost insurers have left.

Most current customers will be insulated from the full increases. To help people afford insurance, the law offers sliding-scale subsidies to people earning less than 400 percent of the federal poverty level, which at $11,880 for a single person means just under $48,000 to qualify. The analysis suggests that most people with a subsidy will see smaller price increases if they switch to the lowest-cost plan. But people earning higher incomes, who pay the full cost of their insurance, will face bigger price increases than before. So will the federal government, which will now pay more in subsidies for everyone else.

The Department of Health and Human Services has been highlighting the role of subsidies in buffering the effects of price changes. In a recent white paper, it estimated that, even if all premiums went up by 25 percent, a large majority of customers could still find plans that would cost them less than $75 a month. That report assumed that the income mix of customers in the marketplace would not change, and that all premiums would increase in perfect concert.

“We remain confident that the majority of marketplace consumers will be able to select a plan for less than $75 per month when open enrollment begins November 1,” said Marjorie Connolly, a department spokeswoman, in an email. “Last year, the average monthly premium for people with marketplace coverage getting tax credits increased just $4.”