Colorado’s top Medicaid official stepped down on Monday, just as a bipartisan bloc of state senators prepared to formally urge Gov. Jared Polis to remove her over what they called years of mismanagement, waste and costly errors inside the state’s largest agency.

One legislator seeking the resignation of Kim Bimestefer, executive direct or of the Department of Health Care Policy and Financing, called the leadership change a “necessary step toward accountability.”

Bimestefer had been under fire from critics, who questioned how health officials have remained in their roles amid what they described as mismanagement at the state Medicaid program, which is beset by allegations of fraud, abuse and runaway spending.

The program’s costs have exploded in the last several years, overtaking K-12 education as the largest line item in the state budget. Jointly funded by the state and federal government, Medicaid provides health coverage to low-income residents, including children, pregnant women, older individuals and people with disabilities. The program is overseen by the Department of Health Care Policy and Financing.

In her resignation statement released by the governor’s office, Bimestefer said she had the privilege of “advancing systems that help Coloradans — often in the most difficult times in their lives — get the care and support they need to rise and thrive.”

Bimestefer acknowledged the difficult situation the state finds itself in.

“Working alongside HCPF leaders, staff and stakeholders, we have navigated one unprecedented challenge after another for over 8 years to protect the state’s most vulnerable, with this current chapter proving to be incredibly difficult,” she said, adding she is confident her successor will “successfully navigate the challenging terrain ahead.”

In accepting her resignation, Polis said Bimestefer has committed her career to serving her fellow Coloradans.

“I am incredibly grateful for her passion and commitment to making our state a better place for everyone, and for her unrelenting quest to really move the needle on health care costs and efficiency,” the governor said.

Just before she resigned, 27 of the Senate’s 35 members were prepared to officially introduce a resolution on Monday, calling for Bimestefer’s removal. The resolution was authored by Sen. Kyle Mullica, D-Thornton.

“I, along with a number of my colleagues in the legislature, have raised serious concerns about the management of HCPF,” Mullica said Monday. “This leadership change is a necessary step toward accountability and gives us a critical opportunity to stabilize the department and put Colorado’s Medicaid program on a sustainable long-term path.”

Colorado Politics obtained a copy of the resolution, which raised several points against Bimestefer’s leadership:

• The “erroneous” removal of 575,605 Coloradans or 33.4% of the state’s Medicaid population from May 2023 to May 2024, “creating a preventable state health-care crisis.” A 2025 report by the Colorado Association of Health Plans said the state’s “overall dis-enrollment rate of 53% is also close to the worst among states with available data, despite it seeing fewer dis-enrollments than Texas and Florida.”
• Overpayment of hundreds of millions of dollars for nonemergency transportation between 2021 and 2024, reimbursing providers at 10 times the rates they should have charged and ignoring alerts from those same providers.
• Overpaying non-wheelchair transportation providers, at an additional cost — according to a JBC analysis — of $33 million in the 2025-26 budget.
• Reimbursing autism providers more than $285 million for improper fee-for-service payments of “dubious value” in 2022 and 2023, according to a Feb. 25 report from the Office of Inspector General for the U.S. Department of Health and Human Services. The state was required to refund the federal government $42.6 million for those improper payments. The OIG noted that Colorado’s fee-for-service Medicaid payments for Applied Behavioral Analysis services in 2019 totaled $60.1 million, but, by 2023, had increased to $163.5 million. Those payments did not comply with federal and state law, the report said, and at least $77.8 million of those payments were “improper.” The OIG also recommended that the state review another $112 million in payments (federal share) to determine if they complied with state and federal law.
• A March 3 letter from the U.S. House Committee on Energy and Commerce, asking Colorado to explain how the state’s spending on Medicaid had surpassed $14.6 billion, of which $8.6 million came from the federal government, and doubling the agency’s spending on Medicaid over the past decade, when enrollment grew by only 7% in the same time period. (The Colorado agency responded by March 17, disputing some of the federal government’s claims.)

“The cumulative effect” of Bimestefer’s “mal-administration” of HCPF has cost Colorado hundreds of millions of dollars and “shifted burdens of care to hospitals and other providers,” the resolution stated.

As a result, Bimestefer no longer enjoys the confidence of the state Senate, the resolution said. The signatories urged Polis to remove her and appoint a successor “who could rebuild confidence in the department.”

Every Republican in the Senate supported the resolution, along with a majority of the chamber’s Democrats, including a mix of both progressive and moderate members.

The resolution came on the heels of the state’s Medicaid program nabbing headlines in recent weeks with allegations of a fraudulent billing ring, improper payments for autism therapy, and exploding costs in a relatively new program meant to provide health care to pregnant women and children illegally staying in the U.S.

The Department of Health Care Policy and Financing has blamed “outrageous behaviors” among providers, while at the same time acknowledging that certain assumptions — such as the health of the immigrant population covered by the new program — have been wrong.

Overspending by HCPF on the Medicaid portion of its budget has been blowing holes in the state budget for at least two years, with an additional $600 million in general funds in 2024-25 and at least $150 million in the 2025-26 budget.

By law, the state must cover that overspending, which state officials have said is tied to higher utilization of health care services by older Coloradans with more expensive health care needs. 

An analysis from a think tank said spending by the Department of Health Care Policy and Financing reached $16 billion in 2025 — a 101% increase from 2015 — while Medicaid enrollment has returned to nearly its 2015 level.

Mullica told Colorado Politics it’s been obvious that HCPF is mismanaged.

“As policymakers, we are having to make some really difficult decisions, making cuts to care for some really vulnerable folks,” he said. 

The issue of mismanagement has been compounded by fraud, waste and abuse, he said.

“It’s across the board, and it’s in the hundreds of millions of dollars, if not billions,” he said.

Mullica said lawmakers now have to figure out how to take care of Medicaid, including in the wake of H.R. 1, the Trump administration’s 2025 budget, which mandates low-income recipients either work or attend school at least half-time or be enrolled in training or volunteering for at least 80 hours per month. In addition, certain Medicaid recipients will be required to be re-certified for benefits every six months, instead of once a year. The requirements could result in loss of coverage. 

Supporters of the federal work requirements have argued they would promote self-sufficiency, reduce government spending, and ensure that welfare programs are sustainable and help those who truly need assistance. Critics said they are unlikely to achieve their purported aims, while cutting off millions of Americans from the help they need.

“I don’t want that hole to be dug any deeper,” and, in the wake of the upcoming Medicaid changes, make the job any harder due to mismanagement by the agency, he said.

“We’re not going to turn a blind eye,” Mullica said. “This isn’t about politics. This is about doing what’s right for the people of Colorado, making sure dollars are best utilized and having accountability.” 

He noted mistrust of government, especially when taxpayers think something is being swept under the rug and that their tax dollars aren’t being used properly. 

“I hope this is an example that we don’t ignore it,” he said. “And that we take accountability and we take action, no matter the letter next to somebody’s name.”

Maureen Tarrant, an HCA HealthONE vice president and a former hospital CEO, earlier said the lack of oversight points to deeper failures.

“(This) is the largest line item in the state budget and you have that kind of mismanagement,” Tarrant said during a forum in February. “That’s not fraud, waste and abuse. That’s mismanagement.”

While Medicaid costs are rising nationwide, Colorado stands out for the share of its budget devoted to the program. Only New Hampshire’s share is higher than Colorado.

Last month, federal prosecutors charged two Medicaid transportation providers with fraud and bilking taxpayers of more than $500,000 in proceeds used for luxury vehicles, jewelry and cosmetic surgery. State officials also said they detected $25 million in abnormal billing — a surge that prompted a new state law and the suspension of dozens of providers.

A federal audit also found Colorado made $77.8 million in improper Medicaid payments for autism therapy after program spending for Applied Behavior Analysis (ABA) surged. ABA is a therapeutic approach that centers on managing symptoms by improving social and communication skills.

“Colorado and the nation are battling unacceptable cost increases due to outrageous behaviors and practices by a subset of disruptive and revenue-maximizing ABA providers,” Marc Williams, a HCPF spokesperson, has said.

Meanwhile, the program that covers pregnant women and children illegally staying in the U.S. was assumed to cost only $27 million. Spending blew past that. It is expected to cost $112 million in the next fiscal year’s budget.

Bimestefer, who has not been directly interviewed by a local news organization on the allegations of fraud and runaway spending, previously served for four years as president and general manager of Cigna’s Mountain States Region, where she began as president of the company’s Taft-Hartley and federal business segment in 2001. Her reasons for leaving Cigna are unknown.

She was removed from her role as president and general manager in 2016, though the reasons are unclear.