Most people know UnitedHealth Group through its subsidiary UnitedHealthcare, the nation’s largest health insurer. Some might know it through its other major subsidiary, Optum Health, the nation’s largest physician employer. But few are familiar with its bank.

In addition to being one of the nation’s largest providers of health savings accounts (HSAs), Optum Financial extends loans to physician practices, increasing their reliance on UnitedHealth Group not only for reimbursement, employment, and claims processing but also for capital. For these reasons, former UnitedHealth Group CEO Andrew Witty promised in 2023 that Optum Financial would be a “very, very material-scale business for us” over the next decade, akin to Optum Health, which, until very recently, investors considered the company’s “crown jewel.”

Optum Financial briefly made headlines in spring 2025 for putting the squeeze on medical practices. A year earlier, it had extended emergency loans to more than 10,000 practices after a cyberattack on its sister subsidiary, Change Healthcare, the nation’s largest health insurance claims processor, paralyzed claims payment processes “for a substantial portion of the medical sector” for several months. Without payment, countless practices faced financial ruin unless they received a monetary lifeline, which Optum Financial provided — until, suddenly, it didn’t. Physician borrowers told CNBC, The New York Times, and The Wall Street Journal that the company demanded they repay hundreds of thousands of dollars in a matter of days; if they did not comply, another subsidiary, UnitedHealthcare, would withhold reimbursements for health care services rendered to cover their debts.

“Optum, in my opinion, is acting like a loan shark trying to rapidly collect,” a pediatric neurologist in New Jersey who received a $535,000 loan told the Times.

But Optum Financial soon lost the media spotlight to its scandal-plagued and increasingly financially challenged parent company. Although UnitedHealth Group deserves the scrutiny, it shouldn’t overshadow deeper questions about Optum Financial. To start, why does a health insurance conglomerate even have a bank?

This policy brief attempts to answer that question by recounting the history of Optum Financial and exploring its growing importance to UnitedHealth Group. It also issues policy recommendations. In the short term, federal policymakers must protect independent physician practices from UnitedHealth Group and other insurance conglomerates, whose anticompetitive business practices drive them to close, sell, or borrow on unfair terms, ultimately driving health care prices higher for patients, health plan sponsors, and taxpayers. In the long term, they must restore the financial viability of independent physician practices and break up the platforms squeezing them out of business.