Common Complaints of Gaps in Medicare Advantage Networks: Rare Federal Enforcement Highlights Concerns
November 20, 2025
KFF Health News: Complaints About Gaps in Medicare Advantage Networks Are Common. Federal Enforcement Is Rare.
As people age, they often face unexpected health challenges alongside the usual aches and pains. The comfort of longstanding relationships with trusted doctors can make difficult news easier to bear. However, losing that support during a health crisis can be daunting. To address this, federal requirements exist to protect individuals with privately run Medicare Advantage coverage when contract disputes arise between healthcare providers and insurers.
Despite these protections, government documents obtained by KFF Health News reveal that the agency responsible for overseeing Medicare Advantage, the Centers for Medicare & Medicaid Services (CMS), rarely enforces the rules designed to ensure that approximately 35 million plan members have access to necessary healthcare providers.
In response to a Freedom of Information Act request covering the past decade, CMS disclosed that it sent letters to only five insurers from 2016 to 2022 after seven of their plans failed to meet provider network adequacy requirements. These lapses could potentially jeopardize patient care.
According to the letters, some plans were found to lack sufficient primary care clinicians, specialists, or hospitals. Officials warned that failing to meet these requirements could lead to marketing freezes, enrollment suspensions, fines, or even plan closures.
CMS has not clarified why so few plans were found to have network violations over the past decade. “The number of identified violations reflects the outcomes of targeted reviews, not a comprehensive audit of all plans in all years,” stated Catherine Howden, a CMS spokesperson.
State officials where violations occurred reported that CMS did not notify them, including directors of the government-funded State Health Insurance Assistance Program, which assists individuals in navigating Medicare.
“It’s hard for me to believe that only seven Medicare Advantage plans violated network rules,” remarked David Lipschutz, co-director of the Center for Medicare Advocacy, a nonprofit organization. “We frequently hear from individuals, especially in rural areas, who must travel long distances to find contracted providers.”
Medicare Advantage has become a popular alternative to traditional Medicare, which serves adults aged 65 and older and some individuals with disabilities. This year, 54% of the 63 million Americans eligible for Advantage plans opted for them. While these plans often provide lower out-of-pocket costs and additional benefits like vision, dental, and hearing care, they typically require members to use a limited network of doctors, hospitals, and other providers. Last year, the federal government allocated approximately $494 billion to Advantage plans for patient care.
In contrast, traditional Medicare has no network restrictions and is accepted by nearly all healthcare providers nationwide.
Conflicts between Medicare Advantage plans and the healthcare providers serving their members are increasingly common. This year alone, at least 38 hospital systems across 23 states have severed ties with 11 Advantage plans due to payment disputes. Over the past three years, separations between Advantage plans and health systems have surged by 66%, according to FTI Consulting, which monitors these disputes.
After March, Medicare Advantage beneficiaries are generally locked into their plans until the annual open enrollment period, which runs from now until December 7 for coverage starting January 1. However, healthcare providers can exit plans at any time.
When providers and insurers part ways, Advantage members risk losing access to their long-time doctors or preferred hospitals mid-year. In such cases, CMS occasionally offers a little-known option called a “special enrollment period” (SEP) that allows members to switch plans or enroll in traditional Medicare midyear.
How CMS determines eligibility for SEPs remains unclear, even to state insurance regulators and U.S. senators overseeing federal health programs. Oregon Senator Ron Wyden and Senator Mark Warner (D-Va.) referenced previous KFF Health News reporting in an October 30 letter to CMS Administrator Mehmet Oz, seeking clarification.
“Despite the serious impacts of SEPs on enrollees and the market, the process of SEP determinations is opaque, leaving enrollees and state regulators in the dark,” they wrote.
“Seniors deserve to know their Medicare plan isn’t going to pull the rug out from under them halfway through the year,” Wyden told KFF Health News.
‘Help Us’
On October 15, Oz addressed Medicare Advantage insurers at a conference organized by the Better Medicare Alliance, a trade group, urging them to assist CMS in combating fraud within the program.
“Be our early-warning system,” he encouraged. “Tell us about problems you’re witnessing. Help us figure out better ways of addressing it.”
In six letters obtained by KFF Health News, CMS officials informed five insurers that their network adequacy violations could affect Advantage members’ access to care. Five letters specified the types of medical specialists or facilities missing from the networks. In three instances, CMS noted that plans could request exceptions to the rules but did not do so. In one letter, CMS requested that the plan allow members to receive out-of-network care at no additional cost. Four letters mandated specific steps to rectify deficiencies, including submitting evidence of additional clinicians added to networks.
Three letters required a “corrective action plan,” set deadlines for resolving issues, and warned that noncompliance could lead to enrollment and marketing suspensions, fines, or plan closures. The remaining three letters served as a “notice of non-compliance,” urging insurers to adhere to legal requirements.
Although CMS considers these letters the initial step in its enforcement process, the agency has not disclosed whether these violations were resolved or if penalties were imposed.
The Medicare Payment Advisory Commission, established by Congress to monitor the program, stated in a June 2024 report that “CMS has the authority to impose intermediate sanctions or civil monetary penalties for noncompliance with network adequacy standards, but it has never done so.”
One of the network adequacy violation letters was sent to Vitality Health Plan of California in November 2020, following the departure of five hospitals and 13 nursing homes in one county and four hospitals in another from the insurer’s network. Two months prior to sending the letter, CMS granted Vitality plan members a special enrollment period.
Beneficiaries appreciated the opportunity, said Marcelo Espiritu, program manager of the Santa Clara County office of California’s Health Insurance Counseling & Advocacy Program. However, Espiritu was unaware at the time that Vitality’s diminished network violated CMS requirements, which Roe indicated jeopardized the health of Vitality’s beneficiaries.
“By not having enough network providers, beneficiaries may not be able to receive necessary services timely, or at all,” Roe wrote.
That’s crucial information for patients, Espiritu emphasized. “People would not be able to receive promised benefits, leading to delays in care and frustration in finding a new plan,” he said. “We would certainly warn people about the plan and remove it from our materials.”
Representatives from Commonwealth Care Alliance, which acquired Vitality in 2022, did not respond to requests for comment.
Network Minimums
Federal law mandates that Medicare Advantage plans include a minimum of 29 types of healthcare providers and 14 kinds of facilities within their networks, accessible within specific distances and travel times. The rules, which vary based on a county’s population and density, also set limits on appointment wait times. Compliance is checked every three years or more frequently if complaints arise.
Networks can differ significantly even within a single county, as the provider minimums apply to the insurer rather than each plan it offers. According to a KFF report, a company can provide the same network to members of multiple plans or create distinct networks for each plan.
In Arizona’s Maricopa County, KFF researchers discovered that UnitedHealthcare offered 12 plans with 12 different networks in 2022. Depending on the plan, customers had access to 37% to 61% of the physicians available to traditional Medicare enrollees.
In early 2016, CMS allowed 900 individuals in an Advantage plan in Illinois run by Harmony, then a WellCare subsidiary, to leave after the Christie Clinic, a large medical practice, exited its provider network. The WellCare plan continued to operate without the clinic. However, in June 2016, CMS notified the plan that losing the Christie Clinic constituted a significant network change with substantial enrollee impact.
Claudia Lennhoff, executive director at Champaign County Health Care Consumers, a government-funded Medicare counseling service that assisted WellCare members, stated that her group was unaware of the letter at the time.
“Not disclosing such information is a violation of trust,” Lennhoff asserted. “It could lead someone to make a decision that will be harmful to them or that they will deeply regret.”
Centene Corp. acquired WellCare in 2020, and representatives for the St. Louis-based company declined to comment on events that occurred before the acquisition.
Two violation letters obtained by KFF Health News were sent to Provider Partners Health Plan of Ohio in 2019 and 2022. The Ohio Department of Insurance was unaware of the violations, according to spokesperson Todd Walker, who noted that CMS did not inform the Ohio Senior Health Insurance Information Program, the state’s free counseling service.
Rick Grindrod, CEO and president of Provider Partners Health Plans, based in Maryland, stated that after CMS reviewed its 2019 network, “we proactively reduced our service area and deferred enrollment in the plan until 2021.”
However, Grindrod noted that the plan enrolled only a small number of members in one county in 2021 and ultimately decided to withdraw from the Ohio market entirely at the end of that year.
After Provider Partners exited Ohio, CMS sent another letter in March 2022 indicating that its 2021 network had gaps in four counties for four types of providers and facilities. CMS requested the plan to comply with network rules by adding more providers.
“We believe CMS’ network adequacy standards are generally clear and appropriate for ensuring beneficiary access,” Grindrod remarked. “While the standards are not difficult to understand, as a provider-sponsored plan with a small footprint, we sometimes face challenges securing contracts with large systems that prioritize larger Medicare Advantage plans.”
In 2021, CMS also issued a violation letter to North Carolina’s Liberty Advantage. CMS did not inform the state’s free counseling service, the Seniors’ Health Insurance Information Program, about the letter, according to its director, Melinda Munden.
Liberty representatives did not respond to requests for comment.
CMS also sent a letter in 2016 to CareSource regarding network deficiencies in some of its Medicare Advantage plans sold in Kentucky and Indiana. The agency requested the company to rectify the issues, including reimbursing any members billed for services from out-of-network doctors.
“In response to the 2016 violations, we promptly implemented a Corrective Action Plan, which included a thorough review of our provider network to ensure adequacy standards were met,” stated Vicki McDonald, a CareSource spokesperson. “CMS approved our plan, and no further action was required.”
By Susan Jaffe
KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.
November 20, 2025
KFF Health News: Complaints About Gaps in Medicare Advantage Networks Are Common. Federal Enforcement Is Rare.
As people age, they often face unexpected health challenges alongside the usual aches and pains. The comfort of longstanding relationships with trusted doctors can make difficult news easier to bear. However, losing that support during a health crisis can be daunting. To address this, federal requirements exist to protect individuals with privately run Medicare Advantage coverage when contract disputes arise between healthcare providers and insurers.
Despite these protections, government documents obtained by KFF Health News reveal that the agency responsible for overseeing Medicare Advantage, the Centers for Medicare & Medicaid Services (CMS), rarely enforces the rules designed to ensure that approximately 35 million plan members have access to necessary healthcare providers.
In response to a Freedom of Information Act request covering the past decade, CMS disclosed that it sent letters to only five insurers from 2016 to 2022 after seven of their plans failed to meet provider network adequacy requirements. These lapses could potentially jeopardize patient care.
According to the letters, some plans were found to lack sufficient primary care clinicians, specialists, or hospitals. Officials warned that failing to meet these requirements could lead to marketing freezes, enrollment suspensions, fines, or even plan closures.
CMS has not clarified why so few plans were found to have network violations over the past decade. “The number of identified violations reflects the outcomes of targeted reviews, not a comprehensive audit of all plans in all years,” stated Catherine Howden, a CMS spokesperson.
State officials where violations occurred reported that CMS did not notify them, including directors of the government-funded State Health Insurance Assistance Program, which assists individuals in navigating Medicare.
“It’s hard for me to believe that only seven Medicare Advantage plans violated network rules,” remarked David Lipschutz, co-director of the Center for Medicare Advocacy, a nonprofit organization. “We frequently hear from individuals, especially in rural areas, who must travel long distances to find contracted providers.”
Medicare Advantage has become a popular alternative to traditional Medicare, which serves adults aged 65 and older and some individuals with disabilities. This year, 54% of the 63 million Americans eligible for Advantage plans opted for them. While these plans often provide lower out-of-pocket costs and additional benefits like vision, dental, and hearing care, they typically require members to use a limited network of doctors, hospitals, and other providers. Last year, the federal government allocated approximately $494 billion to Advantage plans for patient care.
In contrast, traditional Medicare has no network restrictions and is accepted by nearly all healthcare providers nationwide.
Conflicts between Medicare Advantage plans and the healthcare providers serving their members are increasingly common. This year alone, at least 38 hospital systems across 23 states have severed ties with 11 Advantage plans due to payment disputes. Over the past three years, separations between Advantage plans and health systems have surged by 66%, according to FTI Consulting, which monitors these disputes.
After March, Medicare Advantage beneficiaries are generally locked into their plans until the annual open enrollment period, which runs from now until December 7 for coverage starting January 1. However, healthcare providers can exit plans at any time.
When providers and insurers part ways, Advantage members risk losing access to their long-time doctors or preferred hospitals mid-year. In such cases, CMS occasionally offers a little-known option called a “special enrollment period” (SEP) that allows members to switch plans or enroll in traditional Medicare midyear.
How CMS determines eligibility for SEPs remains unclear, even to state insurance regulators and U.S. senators overseeing federal health programs. Oregon Senator Ron Wyden and Senator Mark Warner (D-Va.) referenced previous KFF Health News reporting in an October 30 letter to CMS Administrator Mehmet Oz, seeking clarification.
“Despite the serious impacts of SEPs on enrollees and the market, the process of SEP determinations is opaque, leaving enrollees and state regulators in the dark,” they wrote.
“Seniors deserve to know their Medicare plan isn’t going to pull the rug out from under them halfway through the year,” Wyden told KFF Health News.
‘Help Us’
On October 15, Oz addressed Medicare Advantage insurers at a conference organized by the Better Medicare Alliance, a trade group, urging them to assist CMS in combating fraud within the program.
“Be our early-warning system,” he encouraged. “Tell us about problems you’re witnessing. Help us figure out better ways of addressing it.”
In six letters obtained by KFF Health News, CMS officials informed five insurers that their network adequacy violations could affect Advantage members’ access to care. Five letters specified the types of medical specialists or facilities missing from the networks. In three instances, CMS noted that plans could request exceptions to the rules but did not do so. In one letter, CMS requested that the plan allow members to receive out-of-network care at no additional cost. Four letters mandated specific steps to rectify deficiencies, including submitting evidence of additional clinicians added to networks.
Three letters required a “corrective action plan,” set deadlines for resolving issues, and warned that noncompliance could lead to enrollment and marketing suspensions, fines, or plan closures. The remaining three letters served as a “notice of non-compliance,” urging insurers to adhere to legal requirements.
Although CMS considers these letters the initial step in its enforcement process, the agency has not disclosed whether these violations were resolved or if penalties were imposed.
The Medicare Payment Advisory Commission, established by Congress to monitor the program, stated in a June 2024 report that “CMS has the authority to impose intermediate sanctions or civil monetary penalties for noncompliance with network adequacy standards, but it has never done so.”
One of the network adequacy violation letters was sent to Vitality Health Plan of California in November 2020, following the departure of five hospitals and 13 nursing homes in one county and four hospitals in another from the insurer’s network. Two months prior to sending the letter, CMS granted Vitality plan members a special enrollment period.
Beneficiaries appreciated the opportunity, said Marcelo Espiritu, program manager of the Santa Clara County office of California’s Health Insurance Counseling & Advocacy Program. However, Espiritu was unaware at the time that Vitality’s diminished network violated CMS requirements, which Roe indicated jeopardized the health of Vitality’s beneficiaries.
“By not having enough network providers, beneficiaries may not be able to receive necessary services timely, or at all,” Roe wrote.
That’s crucial information for patients, Espiritu emphasized. “People would not be able to receive promised benefits, leading to delays in care and frustration in finding a new plan,” he said. “We would certainly warn people about the plan and remove it from our materials.”
Representatives from Commonwealth Care Alliance, which acquired Vitality in 2022, did not respond to requests for comment.
Network Minimums
Federal law mandates that Medicare Advantage plans include a minimum of 29 types of healthcare providers and 14 kinds of facilities within their networks, accessible within specific distances and travel times. The rules, which vary based on a county’s population and density, also set limits on appointment wait times. Compliance is checked every three years or more frequently if complaints arise.
Networks can differ significantly even within a single county, as the provider minimums apply to the insurer rather than each plan it offers. According to a KFF report, a company can provide the same network to members of multiple plans or create distinct networks for each plan.
In Arizona’s Maricopa County, KFF researchers discovered that UnitedHealthcare offered 12 plans with 12 different networks in 2022. Depending on the plan, customers had access to 37% to 61% of the physicians available to traditional Medicare enrollees.
In early 2016, CMS allowed 900 individuals in an Advantage plan in Illinois run by Harmony, then a WellCare subsidiary, to leave after the Christie Clinic, a large medical practice, exited its provider network. The WellCare plan continued to operate without the clinic. However, in June 2016, CMS notified the plan that losing the Christie Clinic constituted a significant network change with substantial enrollee impact.
Claudia Lennhoff, executive director at Champaign County Health Care Consumers, a government-funded Medicare counseling service that assisted WellCare members, stated that her group was unaware of the letter at the time.
“Not disclosing such information is a violation of trust,” Lennhoff asserted. “It could lead someone to make a decision that will be harmful to them or that they will deeply regret.”
Centene Corp. acquired WellCare in 2020, and representatives for the St. Louis-based company declined to comment on events that occurred before the acquisition.
Two violation letters obtained by KFF Health News were sent to Provider Partners Health Plan of Ohio in 2019 and 2022. The Ohio Department of Insurance was unaware of the violations, according to spokesperson Todd Walker, who noted that CMS did not inform the Ohio Senior Health Insurance Information Program, the state’s free counseling service.
Rick Grindrod, CEO and president of Provider Partners Health Plans, based in Maryland, stated that after CMS reviewed its 2019 network, “we proactively reduced our service area and deferred enrollment in the plan until 2021.”
However, Grindrod noted that the plan enrolled only a small number of members in one county in 2021 and ultimately decided to withdraw from the Ohio market entirely at the end of that year.
After Provider Partners exited Ohio, CMS sent another letter in March 2022 indicating that its 2021 network had gaps in four counties for four types of providers and facilities. CMS requested the plan to comply with network rules by adding more providers.
“We believe CMS’ network adequacy standards are generally clear and appropriate for ensuring beneficiary access,” Grindrod remarked. “While the standards are not difficult to understand, as a provider-sponsored plan with a small footprint, we sometimes face challenges securing contracts with large systems that prioritize larger Medicare Advantage plans.”
In 2021, CMS also issued a violation letter to North Carolina’s Liberty Advantage. CMS did not inform the state’s free counseling service, the Seniors’ Health Insurance Information Program, about the letter, according to its director, Melinda Munden.
Liberty representatives did not respond to requests for comment.
CMS also sent a letter in 2016 to CareSource regarding network deficiencies in some of its Medicare Advantage plans sold in Kentucky and Indiana. The agency requested the company to rectify the issues, including reimbursing any members billed for services from out-of-network doctors.
“In response to the 2016 violations, we promptly implemented a Corrective Action Plan, which included a thorough review of our provider network to ensure adequacy standards were met,” stated Vicki McDonald, a CareSource spokesperson. “CMS approved our plan, and no further action was required.”
By Susan Jaffe
KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.
