What is the Medicare Advantage?

On October 15, the open enrollment period for Medicare begins running through December 7 for coverage starting in January 2025. In this period, 67 million Medicare eligible seniors can review features of Medicare plans offered in their area, switch from traditional Medicare to a Medicare Advantage (MA) plan (or vice versa), change their MA selection and add/change their Medicare Part D prescription drug plans.

In 2024, Medicare Advantage plans enrolled 33 million seniors and Medicare paid private insurers $462 billion to pay for their care.

But conditions for Medicare Advantage have changed in recent years prompting many to ask ‘what is the Medicare Advantage?’

Background:

Medicare began July 30, 1965 as a key element in President Lyndon Baines Johnson’s Great Society program offering federal-government-paid insurance coverage for seniors at the age of 65.  “Original Medicare” had two parts: Part A to cover hospitals and Part B to cover physicians and outpatient services. In 1972, coverage for adults with disabilities was added, and in 2003, coverage for prescription drugs (Part D) was added.

Its funding comes from payroll taxes paid by employers and their employees, and those who are self-employed PLUS income taxes paid on Social Security benefits, interest earned on the Medicare trust fund’s investments and Part A premiums from people who aren’t eligible for premium-free Part A.

Along the way, Congress authorized seniors the option of accessing Medicare through private insurers aka Part C (Balanced Budget Act of 1997), expanded its scope (Medicare Modernization Act of 2003) and supplemented its funding differential above Original Medicare (Patient Protection and Affordable Care Act 2010) to stimulate enrollment growth. The rationale for MA was straightforward: it offered federal regulators a lab to test care management for seniors with the dual aims of lowering their health costs and improving their health. Private insurers responded. By design, funding for MA was set above Original Medicare rates to encourage private insurer participation.

It worked.  This year, the average MA enrollee had 43 plans from which to choose. By three measures, Medicare Part C has been successful:

• Enrollment growth: Enrollment in MA plans has increased from 31% of Medicare eligible adults in 2014 to 51% in 2024 and is projected to increase in 2025. Notably, enrollment in special needs and employer-sponsored MA plans has increased faster than the individual MA market which is subject to open enrollment periods. Satisfaction appears high (69% of members do not shop for another plan during open enrollment periods) and member churn is low.
• Medicare has saved money: Per the 2024 Medicare Trustees’ Report, MA has contributed to slower growth in Medicare spending than forecast. “The Social Security and Medicare programs both continue to face significant financing issues…The Hospital Insurance (HI) Trust Fund will be able to pay 100% of total scheduled benefits until 2036, 5 years later than reported last year. At that point, that fund’s reserves will become depleted and continuing program income will be sufficient to pay 89% of total scheduled benefits.”
• Private insurer participation has been strong: For health insurers, Medicare Advantage is profitable: PMPM contribution margins are 50-100% higher than individual and group lines of business. And, as CMS payments to MA have tightened, the MA insurer market consolidated with 3 (UnitedHealth, Humana, CVS-Aetna) taking advantage of operating pressures on small players to increase their share to 58% of total enrollment. Advantage: Seniors, Medicare and Corporate Insurance.

But conditions going forward suggest the MA advantage might not be as strong. The market signals are clear:

• Insurer belt tightening: Since 2023, seniors’ use of hospitals, specialty care and prescription drugs has returned to pre-pandemic normalcy cutting into insurer margins. In its CY 2025 Rate Announcement September 27, CMS announced “The average monthly plan premium for all MA plans, which includes MA plans that provide prescription drug coverage and MA Special Needs Plans (SNPs), is projected to decrease from $18.23 in 2024 to $17.00 in 2025. Benefit options will remain stable, including MA supplemental benefit offerings such as hearing, dental, and vision. The amount of rebate dollars, which can be used for supplemental benefits, will remain stable, with a slight increase, from 2024 to 2025. Enrollment in MA is projected to be 35.7 million in 2025, an increase from 2024, with MA enrollment representing approximately 51% of all people enrolled in Medicare.” This translates to lower margins for MA plans, fewer supplemental benefits for enrollees and lower payments to hospitals and physicians.
• Increased regulatory scrutiny: The Medicare Payment Advisory Commission (MedPAC) concluded that MA plans receive payments from CMS that are 122%of spending for similar beneficiaries in traditional Medicare, on average, translating to an estimated $83 billion in overpayments in 2024. Congress is investigating. In 2023, CMS adopted tougher audit standards specific to diagnosis codes used by private MA plans to bill Medicare on behalf of their enrollees. Audits conducted by the U.S. Department of Human Services’ Office of Inspector General (OIG) applying the new standards found the majority of private MA plans guilty of upcoding and thereby overpaid by Medicare. In 2025, cut points used by CMS to award star ratings have been modified resulting in fewer plans getting 4-star ratings that enable their participation in 5% bonus payments—a major reason recent stock declines for UHG, HUM, CVS and others. Regulatory scrutiny of MA plan marketing practices, coding, denials and prior authorization procedures will intensify reflecting bipartisan intent to constrain MA profits.

Understandably, tension between MA insurers and providers has intensified as insurers seek to protect their margins.  The Change Healthcare (CH) cyber-attack (February 21, 2024) that disabled insurer payments to hospitals and physicians stoked animosity since CH is a subsidiary of UnitedHealth Group–the largest sponsor of MA plans and the healthcare juggernaut. Though operating margins for half of U.S. hospitals have recovered, insurer cuts coupled with labor and prescription drug costs have decimated care delivery in almost every community. Participation in MA plan provider networks, once SOP is now a tough call for hospitals, medical groups and other providers.

My take:

What is the Medicare Advantage?

• As a lab for innovation in care management for seniors, it’s promising.
• As an engine to drive lower costs for senior health and extended solvency to the Medicare program, it’s unclear.
• As a platform to shift incentives from fee-for-service to value across the system, it’s helpful.

But until and unless hospitals, physicians, insurers, business leaders and regulators commit to implement a transformed system of health that’s comprehensive, affordable, efficient and accountable, the Medicare Advantage will be marginalized.

In many ways, the headwinds facing MA are part of the larger narrative facing healthcare:

public sentiment against consolidation and corporatization has eroded its cherished trust and confidence. It’s true for insurance, hospitals, prescription drug companies and PBMs. The blame is shared: no one of these owns the moral high ground (though a few organizations in their ranks aspire).