State and county officials are double-checking 30,000 to 40,000 applications filed this fall on the MNsure health insurance exchange to determine if people were incorrectly denied premium subsidies or coverage on public programs.

While most determinations on the exchange were correct, a few of them wrongly denied people access to benefits to which they are entitled next year, MNsure spokeswoman Jenni Bowring-McDonough said. “We are working to ensure that everyone who is eligible receives the right assistance in the right program beginning January 1, 2014,” she said.

Whether the number under review represents most or all of the applications that MNsure has received is unclear, because the organization isn’t releasing its latest enrollment totals until its December board meeting. It is certainly a significant share, however, given that MNsure received only 15,268 completed applications between Oct. 1 and Nov. 2.

The underlying hiccups have been “identified and repaired” and won’t affect future applications on the exchange, Bowring-McDonough said in an e-mailed statement.

MNsure will be contacting people if they received incorrect information; at issue is whether applicants qualified for public programs such as Medical Assistance and MinnesotaCare or for tax credits to lower the costs of premiums for private health plans. Individuals and families are generally eligible for credits to lower premium costs if they earn less than 400 percent of the federal poverty level — or less than $94,000 for a family of four.

No one quirk in the MNsure system prompted the reviews.

In some cases, people were denied eligibility for the state’s publicly funded health care programs because they had indicated that they already have some source of health insurance — a status that doesn’t always disqualify people for state benefits.

In smaller counties where MNsure offered only one silver-level insurance plan to consumers, some people received incorrect information about whether they qualified for tax credits. That’s because eligibility for credits is partly determined by whether people can afford the second-lowest cost silver plan in a marketplace.

Mistakes also might have been made in calculating tax credit eligibility for people who lived in ZIP codes that span two counties.

The exchange was created in part to cover the estimated 490,000 Minnesotans who have no insurance and to provide benefits to those denied affordable plans in the past because of pre-existing medical problems. It was established in connection with the federal Affordable Care Act, known as Obama­care, which requires people to have health insurance as of April 2014 or pay a financial penalty.

In the first few days, many consumers had trouble logging onto the MNsure site and getting past its initial security questions. The site has since become much more stable as state officials installed software fixes and federal officials improved links between the state website and federal databases with tax status and other key federal information.

The latest glitches come in advance of what state officials believe will be a surge in applications.

Though the deadline was recently extended, Minnesotans must enroll by Dec. 23 for their new health benefits to take effect Jan. 1. Open enrollment continues until March 31, though, for coverage taking effect later next year.