Medicare Advantage Rules

Medicare Advantage (Part C) is a privately-administered alternative to traditional Medicare that now covers more than half of all Medicare beneficiaries — roughly 33 million people. Private insurance companies contract with Medicare to provide all Part A and Part B benefits, typically with lower premiums (many plans charge $0/month beyond the Part B premium), built-in out-of-pocket maximums (which traditional Medicare lacks), and extra benefits like dental, vision, and hearing coverage. The tradeoff is network restrictions and prior authorization requirements that traditional Medicare doesn't impose. Whether Medicare Advantage or traditional Medicare is better for you depends heavily on your health status, the specific plans available in your county, and whether your preferred doctors and hospitals are in-network. The program has grown dramatically — from 13% of Medicare enrollment in 2004 to 50%+ today — driven by the extra benefits and the government's per-capita payments to plans, which have historically been higher than what traditional Medicare would spend on the same beneficiaries.

Medicare Advantage (Part C) allows Medicare beneficiaries to receive coverage through private insurance plans that contract with Medicare. Over 50% of Medicare beneficiaries are now enrolled in MA plans.

Legal Authority

• 42 U.S.C. § 1395w-21 — Eligibility, election, and enrollment (Medicare Advantage Part C)
• 42 U.S.C. § 1395w-22 — Benefits and beneficiary protections (required coverage, OOP limits)
• 42 U.S.C. § 1395w-23 — Payments to Medicare Advantage organizations (capitation, risk adjustment, quality bonuses)
• 42 U.S.C. § 1395w-24 — Premiums and bid amounts
• 42 U.S.C. § 1395w-27 — Contracts with Medicare Advantage organizations (sanctions, termination)
• 42 U.S.C. § 1395w-28 — Definitions and special rules (plan types — HMO, PPO, PFFS, SNP)

How It Works

CMS pays MA plans a per-member-per-month capitated rate — a lump sum per enrollee adjusted for health risk using a Hierarchical Condition Category (HCC) model under 42 U.S.C. § 1395w-23. Plans must cover everything Original Medicare covers, including Part A hospital insurance and Part B outpatient coverage. Many plans charge $0 in additional monthly premium because the CMS capitation payment funds required benefits; you still pay your Part B premium ($202.90/month in 2026) regardless of which Medicare path you choose.

The most structurally important MA protection is the mandatory out-of-pocket maximum — required by 42 U.S.C. § 1395w-22 — capped at approximately $8,850 for in-network services in 2026. Original Medicare has no such ceiling: a major illness could expose you to 20% of all Part B expenses indefinitely unless you purchase separate Medigap coverage. Beyond the OOP cap, most MA plans include supplemental benefits Original Medicare doesn't cover: dental, vision, hearing, fitness programs (SilverSneakers), over-the-counter allowances ($25–$200/quarter), and transportation to medical appointments. Most MA plans also integrate Part D prescription drug coverage (called MA-PD plans), giving enrollees access to the Part D $2,000 annual out-of-pocket cap on drug spending.

The tradeoff is network restrictions and prior authorization. HMO-structured MA plans require in-network providers for non-emergency care and typically require primary care referrals for specialists; out-of-network care generally means paying full cost. PPO plans allow out-of-network care at higher cost-sharing. MA plans may require prior authorization for surgeries, specialist referrals, durable medical equipment, and inpatient stays — requirements Original Medicare generally doesn't impose. CMS finalized rules effective 2026 requiring standard prior authorization decisions within 7 days and urgent decisions within 72 hours, with specific clinical reasons for any denial. Star Ratings (1–5 stars) measure plan quality; plans at 4 stars or above receive quality bonus payments from CMS that fund richer benefits. Plan changes are permitted during Open Enrollment (October 15 – December 7) and the MA Open Enrollment Period (January 1 – March 31, one change per period).

How It Affects You

Implementing Regulations

• 42 CFR Part 422 — Medicare Advantage Program (276 sections): CMS's complete regulatory framework for Medicare Advantage. Key subparts:
  • Subpart B (12 sections) — Eligibility, Election, and Enrollment: who can enroll in MA (Medicare Part A + B enrollment required); initial enrollment period (7 months around Part B eligibility); annual open enrollment (Oct 15–Dec 7); special enrollment periods for plan termination, service area changes, loss of other coverage, 5-star plan SEP; deemed enrollment for LIS/dual-eligible beneficiaries
  • Subpart C (30 sections) — Benefits and Beneficiary Protections: MA plans must cover all Medicare-covered services; may offer supplemental benefits (dental, vision, hearing, fitness); out-of-pocket maximum (MOOP) required — capped at $9,350/year in 2026 for in-network services; network adequacy standards (§ 422.116) requiring sufficient providers by specialty and geography; access to emergency and urgently needed services without prior authorization; continuity of care protections when plan exits market
  • Subpart D (9 sections) — Quality Improvement: quality improvement programs required; data collection for Star Ratings; chronic care improvement programs; network quality monitoring
  • Subpart E (13 sections) — Relationships With Providers: prohibition on balance billing Medicare beneficiaries; provider contract requirements; specialty provider access; prompt payment standards; network adequacy maintenance requirements
  • Subpart F (11 sections) — Bid Submission and Plan Approval: annual bid submission process; actuarial equivalence requirements; CMS review and approval of benefits, cost-sharing, and premiums; benchmark calculations and rebate amounts; low-income premium subsidy eligibility
  • Subpart G (15 sections) — Payments to MA Organizations: capitation payment = risk-adjusted benchmark × plan bid / benchmark; hierarchical condition categories (HCC) risk adjustment model; ESRD and hospice carve-out; quality bonus payments for 4+ Star plans
  • Subpart K (19 sections) — Application Procedures and Contracts: MA organization must be licensed as a risk-bearing entity in its service area; application requirements; contract terms; CMS audit rights; annual contract renewal process
  • Subpart M (36 sections) — Grievances, Organization Determinations, and Appeals: beneficiary rights to coverage determination (72-hour standard, 24-hour expedited for pre-service); plan redetermination (7 days); independent review entity reconsideration; ALJ hearing if amount in controversy exceeds $180; same appeals timeline framework as Part D (§ 423)
  • Subpart T/Z (48/4 sections) — Civil Money Penalties and Recovery Audit: enforcement against MA organizations for marketing violations, plan benefit failures, discrimination; penalties up to $25,000 per beneficiary; Recovery Audit Contractor process for identifying overpayments
  • Subpart V (11 sections) — Marketing and Communication: MA plan marketing materials require CMS review and approval; required disclosures (Evidence of Coverage, Summary of Benefits); prohibited sales practices (unsolicited contact, misleading comparisons, gift-giving limitations); 2023 broker compensation rule caps agent commissions
• 42 CFR Part 423 — Medicare Part D prescription drug benefit (plan requirements for MA-PD plans, formulary standards, coverage determinations)
• 42 CFR Part 426 — Review of national/local coverage determinations
• 42 CFR Part 405 — Federal health insurance for the aged and disabled (Part C payment methodology)

Pending Legislation (119th Congress)

• HR3467 — Medicare Advantage Reform (Rep. Schweikert, R-AZ) — Shifts Medicare Advantage to capitated payments, tightens risk adjustment rules, and auto-enrolls beneficiaries into low-premium plans with a 3-year opt-out
• HR6109 — MA Plan Accountability (119th Congress) — Lets CMS cancel Medicare Advantage plans that exceed a 25% reversal rate on prior-authorization denials
• HR6111 — MA Ad Transparency (119th Congress) — Requires Medicare Advantage ads to show prior authorization denial rates, reconsideration approvals, and average approval days
• HR6110 — Automatic MA Reconsideration (119th Congress) — Requires MA plans to automatically reconsider every coverage denial without a beneficiary request
• HR6113 — MA Plan Cap (119th Congress) — Caps each insurer's Medicare Advantage offerings at three plans; requires clear differences for additional plans
• HR6112 — MA Payment Limit (119th Congress) — Bars enrollment in MA plans whose per-enrollee payments exceed Parts A and B fee-for-service costs (with special needs exception)
• HR 6031 — Medicare Advantage Integrity Act: set a 70% floor on MA geographic adjustments; require at least half of benchmark increases go to core benefits. Status: Introduced.
• HR 6114 — Block HHS funds from auto-enrolling Part A and B beneficiaries into Medicare Advantage unless they explicitly choose it. Status: Introduced.
• HR 6361 — Ban AI Denials in Medicare Act: bar HHS from testing prior-authorization models including AI systems in traditional Medicare. Status: Introduced.
• HR 6115 — Require HHS to maintain a searchable online directory of providers in MA networks and original Medicare Parts A and B. Status: Introduced.
• Prior authorization reform: Rules limiting excessive prior auth denials.
• V-BID model: Value-based insurance design expanding supplemental benefits for chronically ill enrollees.

Recent Developments

• MA enrollment reaches 34 million (2026): Medicare Advantage now covers more than half of all Medicare beneficiaries — approximately 34 million of 67 million total enrollees in 2026. The proportion has grown from 25% in 2010 to 51%+ today, driven by zero-premium plans, extra benefits (dental, vision, hearing), and active CMS marketing restrictions on fee-for-service. The growth has prompted scrutiny of MA plan practices: prior authorization denials, claim clawbacks, and network adequacy issues have generated congressional investigations and CMS enforcement actions.
• CY 2026 MA payment rates and Star Ratings enforcement: CMS finalized CY 2026 MA payment rates with a benchmark increase of approximately 5.1% — higher than recent years, reflecting updated risk scores and county benchmarks. Star Ratings reforms implemented for 2026 reduced the number of 4+ star plans (which receive quality bonus payments) from prior years, as CMS tightened performance thresholds. Plans that fell below 4 stars lost the quality bonus — affecting their ability to offer zero-premium plans with extra benefits in 2026. Approximately 40% of MA enrollees are in 4+ star plans.
• Prior authorization scrutiny intensifies: CMS issued a final rule effective January 2026 requiring MA plans to respond to standard prior authorization requests within 7 days and urgent requests within 72 hours — and to provide specific clinical reasons for denials. Plans must implement electronic prior authorization for covered services. A 2024 OIG report found that MA plans denied a significant portion of prior authorization requests that would have been covered under traditional Medicare, and that many appeals of denied PAs were ultimately reversed — raising concerns about inappropriate denials. DOJ has active investigations into MA overbilling through upcoded risk scores and improper prior authorization denials at multiple large insurers.
• CY 2027 proposed changes signal tighter MA regulation: CMS's November 2025 proposed rule for CY 2027 would tighten Star Ratings methodology, revise marketing/communications guardrails (targeting third-party lead generation that CMS characterized as confusing beneficiaries), and require plans to provide more granular data on prior authorization use. CMS also proposed expanding the supplemental benefit reporting requirements — plans must document how supplemental benefits (dental, vision, OTC cards) are actually used by enrollees, responding to evidence that many enrollees don't know or can't use these benefits.