A new health insurer in southeast Minnesota plus more competition in dozens of southern and western counties means more options and a shot at lower premiums for many buying coverage on the state's MNsure exchange.

MNsure announced Friday that consumers in 80 counties next year will see three or more health insurance companies competing on the government-run exchange. This year, only 31 counties in Minnesota are seeing that much competition in the market for individual market coverage.

Average premium increases from returning carriers will range from 1 to 4%, the state Commerce Department said Friday. Monthly costs will vary by geography and could look very different if consumers shop around for a different health plan.

"The actual rate change that a consumer will experience in 2021 can vary depending on factors such as specific plan, geographic rating area and age," Commerce said in a statement.

A 40-year-old in Rochester who currently buys the "benchmark" policy in Olmsted County and switches insurers to buy next year's benchmark health plan would see a discount in premium costs of 21%, or more than $100 per month. Commerce says that more than 50 counties across the state are seeing discounts in the price of their benchmark health plans.

In Hennepin County, the benchmark plan's monthly cost for a 40-year-old will increase by less than 2%, or about $4.40 per month. In Duluth, the cost of the benchmark health plan will increase by 8%, or about $26 per month.

About 160,000 people buy coverage in Minnesota's individual market, which generally serves self-employed people and those who don't get health benefits through their job.

Minnesota launched the MNsure exchange in 2013 as part of the federal Affordable Care Act (ACA). Consumers use the exchange to buy individual market coverage and see if they qualify for tax credits that discount premium costs.

The number of carriers selling individual market coverage across the Twin Cities and counties in northeast Minnesota is mostly holding steady, according to a Star Tribune review of state materials released Friday. Across the southern and western parts of the state, the number of insurers selling individual coverage is growing from two carriers to three or, in some cases, four insurers.

"This year, we are able to offer even more options for Minnesotans to find the health insurance they need, along with access to financial benefits to help lower the cost of coverage," said Nate Clark, the MNsure chief executive, in a statement.

Open enrollment for individual health plans sold on MNsure runs Nov. 1 through Dec. 22.

Bloomington-based HealthPartners and Minneapolis-based UCare are expanding their service areas, Commerce said Friday. Minnetonka-based Medica and the HMO from Eagan-based Blue Cross and Blue Shield of Minnesota will continue to offer individual market plans statewide next year.

Quartz, an insurer based in Madison, Wis., will newly sell individual coverage via MNsure in five counties in southeast Minnesota at rates 6% to 38% below competitors, the company said in a statement. Rochester-based Mayo Clinic is not in the health plan's network of doctors and hospitals.

"We think consumers will still find Quartz as an attractive option with our provider partners at Gundersen Health System and Olmsted Medical Center," the insurer said in a statement.

Quartz is jointly owned by Gundersen in La Crosse, Wis., along with the health system at the University of Wisconsin-Madison and UnityPoint Health, which operates hospitals and clinics in Illinois, Iowa and Wisconsin.

The ACA relies on insurers competing on state exchanges like MNsure to help control rising premium costs. Prices vary by county and age.

In each county, the "benchmark" plan is the health insurance option that sells for the second-lowest premium among all those with "silver" level benefits. The benchmark plan can change from year to year, so consumers that want to remain in the benchmark option might have to switch insurance companies.

In Hennepin County, the premium for a 40-year-old buying the benchmark policy is increasing from $274.74 per month this year to $279.14 in 2021. In Duluth, the benchmark plan for a 40-year-old is increasing from $328.35 per month to $354.41.

In Olmsted County, a 40-year-old buying the benchmark plan will pay $388.66 per month next year — a savings compared with this year's monthly cost of $492.06. The benchmark plan in Rochester next year will be sold by Quartz, the new insurer, so Rochester consumers would need to switch to the new carrier to see the savings.

Commerce said about 60,000 consumers in the individual market obtain tax credits via MNsure. For those consumers, lower benchmark premiums in a county affect the value of tax credits they will receive.

Overall, the premium increases announced Friday are relatively modest compared with the long-term trend with health care costs, which typically rise faster than general inflation.

Commerce approved average rate changes that vary by carrier including Blue Cross HMO (+4.21%), HealthPartners (+0.67%), Medica (+2.42%) and UCare (+1.6%). Golden Valley-based PreferredOne also sells individual market policies, Commerce said, but not through the MNsure exchange.

Twitter: @chrissnowbeck