A new federal audit looks back at the troubled rollout of MNsure and finds that the state's health insurance exchange didn't always properly assess whether enrollees were eligible for financial help.

In two cases, federal auditors found that enrollees qualified for federal tax credits even though they said they had access to coverage from another source — a circumstance that should block subsidies.

In three cases, MNsure did not try to resolve inconsistencies in an applicant's eligibility data, according to the audit by the Office of Inspector General at the U.S. Department of Health and Human Services. It looked at 45 applications from October 2013 through March 2014.

"Without resolving inconsistencies … the Minnesota Marketplace could not ensure that the applicant meets each of the eligibility requirements for enrollment in a [health plan] and, when applicable, for insurance affordability programs," auditors wrote in a report being released Tuesday.

MNsure said it has since fixed the defects that resulted in two people qualifying for tax credits when they indicated access to coverage elsewhere.

On data inconsistencies, MNsure said that during the time period covered by the report, the exchange had suspended sending notices about such issues because of technical problems. The exchange has since made "substantial progress," MNsure said in a statement.

"All of the findings in this audit have either been addressed, or are on track to be resolved in the coming months," said MNsure CEO Allison O'Toole in an interview.

The audit looked at the portion of MNsure that individuals use to buy health insurance policies from private insurers. A different audit last month from state Legislative Auditor James Nobles looked at people who enrolled in public insurance programs through MNsure and found that thousands of people in early 2015 might have received coverage when they didn't qualify.

Minnesota created the MNsure health insurance exchange in 2013 to implement the federal Affordable Care Act, which required new exchange marketplaces for all 50 states. Most states are covered by the federal government's HealthCare.gov exchange, but Minnesota was one of more than a dozen to create its own online system.

MNsure is one of seven state-based insurance exchanges being reviewed by the Office of Inspector General. An audit of Kentucky's exchange released in October found that its internal controls were generally effective. Subsequent reports found problems with the exchanges in Colorado and Washington.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck