Jeremiah Whitten got used to glancing, at best, at the insurance statements and benefit explanations that flooded his mail amid chemotherapy and a bone-marrow transplant for an aggressive cancer. But the Chaska man had a gut feeling last week that a letter from Carver County Community Social Services required closer attention.

The first sentence, in bold, confirmed his fear: “Health Plan Disenrollment Notice.”

It was Whitten’s first warning — four days before he would lose his benefits.

“Canceling my health insurance would cause calamity to my life,” said Whitten, 58, who takes 25 pills daily for pain relief and to prevent his body from rejecting the transplant.

Whitten appears to have been one of multiple casualties of the state’s turbulent conversion for 2015 to a MNsure electronic system for determining eligibility for state-subsidized Medical Assistance or MinnesotaCare programs.

Scrambling to make 180,000 overdue renewal determinations this summer due to glitches in the system, the state pulled in extra staff. Eventually it determined that 40,000 low-income Minnesotans would be dropped from coverage by Sept. 1 because they no longer qualified or failed to turn in paperwork.

But it appears mistakes were made. Whitten lost his coverage despite sending in a form seeking renewal of his benefits in March. He received no notice until late August that his coverage was in jeopardy. Navigator agencies such as Portico Healthnet, which help Minnesotans access health benefits, have received similar calls and visits over the past month from others who believe they should still be covered.

“Clients are coming to us so frustrated,” said Rebecca Lozano, Portico’s outreach director. “They’ve already tried to call three different places and ended up on a wild-goose chase.”

A spokeswoman for the Minnesota Department of Human Services, the oversight agency for the state-subsidized health plans, said an administrative error resulted in some incorrect determinations, and that as many as 500 people who received disenrollment notices have had their benefits restored without interruption.

Disenrollment letters to the group of 40,000 starting going out in mid-August, but the explanations of why people were being cut off were vague, said Leigh Grauman, director of training and policy implementation for Portico. “It was kind of a mad dash for us to call and figure out what was needed.”

Complicating the process is that many state workers who would otherwise handle phone lines have been processing applications, she said. So even Portico workers have struggled to call and check on the status of applications they helped people complete.

Adding to the panic for Whitten were his immediate medical needs. While his cancer is in remission — he was diagnosed with Burkitt lymphoma in March 2014 — he needs to take costly medications and maintain regular checkups. On Monday, he learned a persistent mark on his nose was a skin cancer and would need to be surgically removed this month.

On Wednesday, a human services official called Whitten and apologized for an error that incorrectly terminated his benefits. The resumption of his health coverage was fortuitous, because late Thursday he was hospitalized for pneumonia.

Whitten managed media relations for the Park Nicollet health system until his position was eliminated in the organization’s merger with HealthPartners. A few months later, he suffered pain in his back and legs and the cancer was discovered while he was unemployed and uninsured.

Due to infection risks while he received his bone marrow transplant at the University of Minnesota Medical Center, Whitten was largely confined to the Hope Lodge housing facility for cancer patients. He was in a wheelchair and discouraged from going outside — a sister drove him periodically to Target for shopping trips, but only if he wore a mask and remained in the car.

He remembers completing an application to renew his HealthPartners Medical Assistance plan, and handing it to a friend to mail on March 19 because he was too weak to do it himself. Or at least he thought it was his application.

After being contacted this Wednesday about the case, state officials discovered that Whitten had sent them a MNsure form that determined his eligibility but wasn’t the actual application. He said he never received the proper renewal form in the mail.

That is a common refrain among the people coming to Portico because they also lost their coverage this month.

Problems involve both the state Medical Assistance program, which serves people at or near the poverty line, and MinnesotaCare, for those with slightly higher incomes.

“For a lot of people, they had never actually received the renewal paperwork,” Lozano said. “While they may have known they needed to renew, they didn’t know the way to go about it.”