LADUE, Mo. — For four consecutive days in January, Margaret Hvatum ran a 5K, a 10K, a half marathon and a full marathon. The 70-year-old covered a combined distance that is almost equivalent to running Manhattan four times.
By the end of the month, he was in a hospital bed.
Hvatum, a part-time computer science teacher, has a weakened immune system due to a rare condition known as primary immunodeficiency, which makes it difficult for her body to fight infections. Before his diagnosis in 2005, he had four attacks of shingles, a painful rash caused by a virus.
For more than a decade he relied on an expensive medication to treat his chronic illness and relied on his insurance to pay for it.
Then the refusal letters arrived.
The medical service
To boost his weakened immune system, he relies on Hizentra, which is made up of antibodies extracted from donated blood plasma.
At her home near St. Louis, Hvatum is able to administer the complex medication herself. He uses a large syringe to draw medication from a vial and loads the syringe into a plastic device that looks like a toy Nerf gun. He turns a blue plastic dial that activates a steady drip of medication, which snakes through a plastic tube until it enters his leg through a needle.
the bill
$8,141.94: Full charges for a 28-day supply of Hizentra without insurance coverage.
After her Medicare Advantage plan through Humana denied payment for the medication in January, she skipped several weekly doses.
The Billing Problem: Prior Authorization
Hvatum became embroiled in the controversial process known as prior authorization, which often requires patients or their medical team to get approval from an insurance company before obtaining medications or treatment.
Earlier this year, after Hvatum switched Medicare Advantage plans, he received a letter saying that Humana, his new company, had denied his “prescription prior authorization request” for Hizentra. Authorization from your previous insurer did not transfer.
Without the medication, Hvatum developed a urinary tract infection that sent her to the emergency room on January 30. Although it is a common infection, his doctor advised him to go there because people with his condition can get sick and deteriorate quickly, he said.
That ER visit turned into an overnight stay in the hospital. That turned into hospital bills of more than $18,000, and again her insurance denied payment, this time saying she wasn't sick enough to need hospital care.
Hvatum's experience with prior authorization is not unique.
Medicare Advantage plans reviewed nearly 53 million prior authorization requests in 2024, according to KFF. That equates to almost two reviews for every person enrolled in the program.
It's common for Medicare Advantage plans to deny payment for care, which helps them make profits, said Carrie Graham, director of the Medicare Policy Initiative at Georgetown University's Center for Health Insurance Reforms.
The government pays a monthly sum to Medicare Advantage insurers to cover each member's care. “They make a profit if the care that person receives in that year is less than the amount they receive,” Graham said.
More than half of eligible Medicare beneficiaries choose Medicare Advantage insurance coverage. In 2026, approximately 35 million people chose one of these private policies offered by insurance companies.
Humana is a dominant player in this space. Nearly half of all Medicare Advantage enrollees nationwide are covered by UnitedHealth Group or Humana, according to KFF.
The murder of UnitedHealthcare CEO Brian Thompson sparked new scrutiny of prior authorization. Last summer, months after his death, the nation's largest insurers, including Humana, signed a pledge that outlined a handful of commitments to ease the burden on patients.
For example, insurers committed to reducing the number of services that would require prior authorization approval. They also promised to reduce delays by honoring existing prior authorizations for a 90-day period when patients change plans.
That is not what happened in the Hvatum case.
Humana said this commitment to comply with existing approvals has limitations. “These commitments are for medical services only and do not apply to prescription drugs,” said spokesman Mark Taylor.
Humana declined to comment on the details of Hvatum's case, although it agreed to waive its privacy rights and gave the insurer permission to comment.
While acknowledging that the prior authorization process can be deeply frustrating for patients, Humana said it “builds important checks and balances into the health care system by verifying that treatments and care delivery are in the best interest of patient safety and quality of care, while protecting taxpayer dollars.”
In July 2025, Humana said it would eliminate one-third of prior authorization requirements for outpatient services.
“We are committed to making the process faster and smoother for patients and providers,” Humana said in a statement Taylor provided to KFF Health News.
The resolution
Hvatum appealed, and in late January, Humana reversed its initial payment denial for Hizentra, allowing him to pay for his medications again.
But the approval had a catch: It expires at the end of the year, after which it would have to get approved again.
Hvatum has since switched to a different medication, and may not be left in any more medical bill fights like this one. She and her husband are considering moving to Norway, a place with universal healthcare. He is a citizen there, which could give him a path to public health coverage.
The industry's promises of change are too little, too late for Hvatum.
According to her, she has done her part. Running is her outlet, perhaps an obsession, and it keeps her healthy. Dozens of medals and trophies are hidden in his house. Some sit at a white wicker side table, next to family photos, candles and framed St. Louis Cardinals memorabilia. Over a large window in the kitchen, the medals hang from ribbons of all colors, made to look like personalized window curtains.
“I've done everything I can to be healthy,” Hvatum said, sitting at her dining room table in her running gear. His printed T-shirt read: “If you find him on the ground, drag him to the finish line.”
The takeaway
Data shows that patients must appeal prior authorizations, because those who do so often have their denials reversed, Graham said. In fact, 81% of Medicare Advantage appeals were fully or partially overturned in 2024, according to KFF.
Relatively few people appeal because “it's an exhausting process,” Graham said. The onus falls on patients, and doctors are frustrated too.
It's not just Medicare Advantage plans that subject enrollees to prior authorization approvals. It is prevalent in other types of coverage and has provoked negative reactions from the public. Graham believes the public outcry instigated the industry's commitment to change.
Hvatum is well versed in filing appeals. He filed another appeal with Humana after the insurer denied payment for his hospital stay in January. Humana again revoked its refusal to pay in his case.
Hvatum blames Humana for his trip to the hospital in January. If Humana had approved his Hizentra, he said, he could have avoided hospital care altogether.
In March he suffered a stroke. Humana also denied coverage for that hospital stay.
Humana determined that it was unreasonable for the doctor who admitted Hvatum to think she would need to stay at least two nights, the threshold for approval. “He had a small stroke,” Humana's denial letter said.
Hvatum noted that the letter was dated March 25, two days after his hospitalization. Humana reversed its denial two weeks after Hvatum appealed.
“They love to send you denials quickly,” Hvatum said. “Approvals take longer.”
Bill of the Month is a collaborative investigation by KFF Health News and The Washington Post's Well+Being that analyzes and explains medical bills. Since 2018, this series has helped many patients and readers reduce their medical bills and has been cited in statehouses, the U.S. Capitol, and the White House. Do you have a confusing or scandalous medical bill you want to share? Tell us!
