Medicare Advantage (MA) plans vary significantly in how they treat providers — on reimbursement rates, prior authorization burden, credentialing speed, and responsiveness to billing disputes. This guide covers the major national MCOs from a provider’s perspective: what you should know before contracting, what you should watch for after, and which plans have earned a reputation for making provider life harder than it needs to be.
⚠️ Important: This is a provider-facing reference based on publicly available information, industry surveys, and widely reported experience patterns. Reimbursement rates vary by geography, specialty, and contract negotiation. What’s true nationally may not reflect your specific region or contract terms. Use this as a starting framework, not a substitute for reading your actual contract.
UnitedHealthcare (UHC) / Optum
Market position: Largest Medicare Advantage insurer in the US. Operates under multiple brand names including AARP Medicare Advantage (underwritten by UHC).
Reimbursement: UHC typically reimburses at a percentage of Medicare rates negotiated by contract. Rates vary significantly — some specialty contracts are competitive; others are notably below CMS fee schedule. The acquisition of provider groups through Optum has created vertical integration tension: UHC/Optum increasingly steers patients toward owned provider networks.
Prior authorization: High prior authorization volume. UHC expanded PA requirements ahead of CMS’s 2024 rules and has been consistently named in AMA surveys as having the highest PA burden of any major insurer. Behavioral health, post-acute, and high-cost procedures are especially heavily reviewed.
Credentialing: Slow. UHC credentialing runs 90–120 days in most regions. The CAQH integration is standard but initial credentialing often requires extensive follow-up. Delegated credentialing groups (Optum-affiliated practices) move faster.
Dispute resolution: Tiered appeals process exists but is known to be slow. The 2024 DOJ and state AG attention on MA prior authorization denials has included UHC-related plans prominently.
What to watch: Retroactive audits on high-utilization specialties. Risk adjustment audit programs (RADV) that can trigger overpayment demands months or years after claim payment.
Humana
Market position: Second-largest MA insurer nationally, with particular density in the Southeast, Southwest, and rural markets. Known for HMO-model plans.
Reimbursement: Generally at or near Medicare rates for contracted providers; HMO plans require referral from a PCP, which creates patient flow constraints.
Prior authorization: Moderate burden relative to UHC — still significant for post-acute, DME, and certain behavioral health services. Humana has invested in PA automation; turnaround times have improved in recent years but denial rates remain notable.
Credentialing: 60–90 days typical. Humana uses CAQH and has a reasonably functional provider portal. Delegated credentialing through affiliated medical groups is available in some markets.
Behavioral health: Humana MA plans have been criticized for carve-out behavioral health management (often through LifeSynch or similar third parties), which adds a credentialing and authorization layer separate from the MA plan itself.
What to watch: The “clinical coverage policies” addenda to your contract — Humana publishes these separately and they govern coverage determinations. Review them before signing.
Aetna / CVS Health
Reimbursement: Aetna MA rates have historically been competitive for primary care and moderate for specialties. Since the CVS acquisition, there has been growing focus on directing MA members to CVS MinuteClinic and CVS Health Hub locations, creating some primary care referral competition in dense markets.
Prior authorization: Moderate-to-high. Aetna has one of the more technology-forward PA systems (Naviguard integration, electronic PA requests). PA denial rates are meaningful but the appeals process is reasonably responsive compared to UHC.
Credentialing: 60–90 days. Aetna has improved provider portal functionality post-CVS acquisition.
What to watch: The growing CVS/Aetna vertical integration in primary care. In markets where CVS Health Hubs are active, expect some shift in MA patient referral patterns.
Blue Cross Blue Shield (BCBS) Plans
Market position: BCBS plans are independent licensees — each state’s BCBS plan is separately managed. National generalizations apply less here than to the other major insurers. A Florida Blue plan is a different contracting and credentialing experience than Highmark or BCBS of Michigan.
Reimbursement: Varies widely by state. Some BCBS MA plans are among the best payers for specialty care in their markets; others are not.
Prior authorization: Varies. Some state plans use AIM Specialty Health or other third-party PA organizations for certain service lines.
Credentialing: Generally 60–90 days. Because each plan is separate, moving between states or credentialing with multiple BCBS plans means separate applications.
What to watch: The plan-specific addenda and clinical policies. More than most carriers, what “BCBS” means depends entirely on which state’s plan you’re dealing with.
Cigna / Evernorth
Market position: Smaller MA footprint than UHC or Humana, with geographic concentration in certain markets. Cigna’s MA growth has been selective.
Reimbursement: Rates comparable to other major insurers; some specialty contracts have been competitive.
Prior authorization: Moderate burden. Cigna’s behavioral health (managed through Evernorth) can be a separate credentialing and PA process from the MA plan itself.
Credentialing: 60–90 days.
What to watch: The Evernorth behavioral health carve-out — if you’re a behavioral health provider, you may be credentialing with Evernorth separately from Cigna MA.
Regional and smaller MA plans
Several regional MA plans consistently outperform national carriers on provider experience metrics:
- Kaiser Permanente MA plans — staff model; credentialing means joining the group, not a fee-for-service arrangement
- Geisinger Gold (PA) — integrated system; cooperative if you’re in the network
- Harvard Pilgrim / Point32Health (NE) — generally favorable provider relations reputation
- SelectHealth (UT, ID) — integrated Intermountain Health model, strong payer reputation
Regional plans often have lower PA burden and faster credentialing than national carriers because their smaller size requires closer provider relationships to maintain network adequacy.
The plans providers warn each other about
These patterns are documented in AMA survey data, peer-reviewed analysis of MA denial rates, and widely reported provider experience — not isolated anecdotes:
Highest prior authorization burden (AMA surveys, consistent): UnitedHealthcare, Humana (for certain service lines), Cigna
Highest denial rates for initially submitted claims: Data varies by specialty. CMS’s MA encounter data analysis and KFF research consistently show some MA plans deny at 2–4× the rate of others for the same service types.
Slowest credentialing in-region: Generally the large nationals in dense markets where their credentialing volume overwhelms process capacity.
Behavioral health carve-outs as a barrier: Plans that separately carve behavioral health to Beacon, Evernorth, or MHNet require separate credentialing and have separate PA processes — effectively doubling the administrative burden for behavioral health providers.
Before you contract with any MA plan
- Check the fee schedule addendum, not just the base contract. The contract language is standard; the rates are in the addendum. Always request the full fee schedule for your top 20 billing codes before signing.
- Ask about PA requirements for your specialty. Request the plan’s clinical coverage policies for your service lines before credentialing. PA burden is not always disclosed upfront.
- Check network adequacy in your area. If the plan is at capacity for your specialty, your contract may be accepted but patients won’t be directed to you.
- Ask about timely payment terms. Most MA plans contractually owe payment within 30 days of clean claim receipt. Note whether the contract specifies clean claim processing timelines.
- Understand the arbitration clause. Most MA contracts require binding arbitration for billing disputes, limiting your recourse outside the plan’s appeals process.
Ask Mae if you have questions about a specific plan’s requirements or how to evaluate a contract before signing.