The number of Minnesotans picking a private health plan through MNsure during the most recent open-enrollment period was up slightly over the comparable period last year — modest growth at a time when sign-ups have been down in several other states and the Trump administration has promoted alternatives to coverage under the federal Affordable Care Act (ACA).

During the open-enrollment period that started in November and ended Sunday night, 123,731 people used Minnesota's health insurance exchange to select a health plan for individuals and families. That was an increase of nearly 400 people, or less than 1 percent, compared with the open-enrollment tally from a year ago.

MNsure officials said they didn't see any obvious effect on sign-ups from alternate forms of coverage being pushed at the federal level or from a 2017 tax law that means the federal government starting this year won't enforce a mandate for most individuals to have health insurance.

"We saw that many of the things that folks thought would undercut the market had no effect here in Minnesota," MNsure CEO Nate Clark said in a statement. "MNsure bucked the national trend."

MNsure is a government-run website that's an option for individuals under age 65 who are self-employed or don't get health insurance from their employer. Minnesota launched the health insurance exchange in 2014 to implement the ACA, which provides income-based tax credits to many who buy coverage through one of its insurance exchanges.

Individuals don't have to buy coverage through MNsure and can purchase instead directly from health insurers. Numbers aren't expected for at least another month showing enrollment trends in this "off-exchange" portion of the individual market.

The figures released Wednesday show a fifth consecutive year of growth in open-enrollment sign-ups at MNsure, although the year-over-year rate of increase was much smaller than previous years. Premiums on average are down for 2019 in the individual market, which explains why the projected value of cumulative tax credits being used by MNsure shoppers this year is expected to decline by 25 percent to about $219 million.

The federal government's HeathCare.gov website, which serves as the exchange in more than 30 states, saw open-enrollment sign-ups fall by more than 300,000 people, or about 4 percent, to 8.4 million, according to a government report this month. Health-policy experts say one possible explanation for the difference is that Minnesota and other states that run their own health exchanges have maintained spending on outreach and enrollment efforts, whereas the federal government has cut back spending.

The ACA banned carriers from denying coverage to people based on pre-existing health conditions and coupled the requirement with tax penalties for individuals who don't have health insurance. A tax bill signed into law in late 2017 by President Donald Trump eliminated enforcement of the ACA's "individual mandate" for people to buy coverage.

The Trump administration has issued rules to promote short-term health plans and association health plans that could provide lower-cost options for some people buying coverage in the individual market, but the effect of the federal rules varies by state. Minnesota, for example, limits the duration of short-term health plans in ways that make the coverage less of an alternative to the ACA-compliant individual market.

Numbers released Wednesday show that Minneapolis-based UCare had the largest share of the MNsure market during open enrollment at 33 percent. Thirty-seven percent of those picking a plan on MNsure were age 55 or older, the same share as last year.

Compared with open enrollment for 2018, the health exchange saw its first decline in the share of shoppers picking "bronze" plans, which have the lowest premiums and highest deductibles. There also was an increase in the share of MNsure users picking "gold" plans, which have high premiums and low deductibles.

"This is the first time we've seen bronze decrease, and we saw our [overall] enrollment hold steady," Clark said. "I do think the plan selection is going to be driven in many cases by the cost of the premium, and we know premiums were lower this year."

After three years of big premium jumps, Minnesota's individual market for 2019 is seeing a second year of flat or declining premiums. The average benchmark premium across Minnesota in 2019 for a 40-year-old nonsmoker is $326 per month, a decline of 15 percent from the comparable rate this year, according to the Kaiser Family Foundation.