Open enrollment is underway at two agricultural cooperative health plans that for a second year will provide an alternative to the state's individual market and MNsure health insurance exchange.

Whereas average premiums are declining next year for health plans sold via MNsure, organizers say the co-op rates will be flat or increasing for 2019.

Even so, the co-ops said they are planning for growth. Critics fear farmer health plans might hurt the individual market under the federal Affordable Care Act (ACA) by pulling healthy people out of the MNsure risk pool, but so far the co-op impact has been limited.

"We expect a pretty big bump," said Abir Sen of Gravie, a health benefits company in Minneapolis that helps people sign up for the plan sponsored by Arden Hills-based Land O'Lakes. "If you're doubling the eligibles, you want to double the enrollment, at least. So, we'll see."

Minnesota lawmakers in 2017 cleared the way for co-op health plans as an alternative to the state's individual market, which suffered several years of steep price increases. The individual market serves self-employed people under age 65, a group that includes many farmers.

The law for agricultural cooperative health plans (ACHPs) let farmers in certain circumstances band together in "self-insured" health plans like those used by many large employers. Co-op coverage is open only to members who actively work in production agriculture, the law says, or provide direct services to the state's industry.

Two groups launched ACHPs for 2018 — Land O'Lakes and St. Paul-based 40 Square Cooperative Solutions — and enrolled more than 1,700 people combined. There have been concerns that the farmer health plans might pull relatively healthy people from the risk pool at MNsure and the broader individual market, thereby driving up rates for those consumers.

But the first-year sign-up numbers led some experts to suggest the initial effect from the farmer health plans would be small.

For 2019, Sen said "the prices remained flat" for coverage in the Land O'Lakes plan, which had more than 700 enrollees in January. The cooperative is making the coverage available next year to more farmers as well as their employees.

Charlene Vrieze, executive director at 40 Square, said premiums with her group are going up by an average of 9.3 percent in part because of medical trend. In response to member feedback, 40 Square is launching an additional health plan offering for 2019 with a higher deductible.

"We hope to double our current level of lives to 2,200 total," Vrieze wrote in an e-mail.

About 155,000 state residents purchase individual health insurance policies, which are an option for people under age 65 who are self-employed or don't get coverage from their employer.

The market saw significant changes starting in 2014 when the federal ACA made it illegal for health insurers to deny coverage to individuals with pre-existing health conditions. At that time, about 293,000 Minnesotans bought individual coverage. The market has shrunk because of a series of big premium increases.

Minnesota launched the MNsure exchange in 2014 to implement the ACA, which provides income-based tax credits to people who buy individual coverage through the government-run website.

Twitter: @chrissnowbeck