People who still qualify for subsidies but earn a bit more have other factors to consider. Some may see their subsidies shrink a bit this year — that’s because prices on silver plans, which are used to calculate subsidies, have declined slightly. In some places, those subsidies may still be large enough to offset most of the monthly premium costs of, say, a bronze plan or to make a gold plan more reasonable.

If you’re not eligible for a subsidy, it could be worthwhile to consider plans that comply with the law but are offered off the exchange directly through an insurer or a broker. Given the inflated prices of certain silver plans, buying the same metal plan outside the exchange could save you roughly 10 percent on average, according to Cynthia Cox, a health insurance policy expert at the Kaiser Family Foundation.

A 40-year-old single person would pay about $480 a month on average for a full- price, benchmark silver plan on the state and federal exchanges, Ms. Cox said. Costs can jump quickly from there. “If you need to cover other family members,” Ms. Cox said, “it starts looking more like another mortgage payment.”

Making the calculation

When analyzing plans, start with what you know. Are your doctors and preferred hospitals in the network? It can change year to year. (Few plans offer out-of-network coverage; when they do, it’s limited.) Which cost-sharing tiers do your prescriptions fall into, and how much of the costs are covered? How will the costs of treating continuing health conditions be split ?

“It’s harder than shopping on Amazon and looking at a list of prices and finding the cheapest one,” said Chris Sloan, a director at Avalere Health, a health care research and consulting firm .

The examples here illustrate some options with premium costs for a family of four: two 30-year-old adults and two children.