1. Provider networks are narrow compared to Original Medicare networks.
Original Medicare is widely accepted by physicians, with only a small share opting out. In contrast, many MA plans limit care to contracted provider networks. This can restrict access to certain specialists or hospitals and may cause disruptions if a preferred doctor is not included in the plan’s network.

2. Out‑of‑pocket costs can be higher than they appear.
While many MA plans advertise low or $0 monthly premiums, members often face copayments, coinsurance, and deductibles. In some cases, daily hospital copays or other cost‑sharing features can result in higher costs than beneficiaries would face under Original Medicare paired with a Medicare Supplemental Insurance policy. Though MA plans include an annual out‑of‑pocket limit, that ceiling can be financially burdensome. 

3. Prior authorization is common.
MA plans frequently require prior authorization before covering services such as hospital stays, surgeries, or post‑acute care. Most requests are approved, but the process can delay treatment or create administrative challenges.

4. Annual plan benefits, networks, and costs can change.
Each year, insurers offering MA plans may adjust provider networks, benefits, and cost‑sharing structures. Coverage that works well one year may not offer the same value the next, and beneficiaries must review changes during annual enrollment periods.

5. Returning to Original Medicare can be difficult.
Switching back to Original Medicare from MA is permitted during certain enrollment periods, but obtaining a Medigap policy afterward is not always guaranteed. Federal protections provide limited windows for guaranteed‑issue Medigap enrollment, and outside those times insurers may deny coverage or charge higher premiums.

6. Strict requirements for nursing care facilities may apply.
Coverage of skilled nursing facility (SNF) stays is a common concern for enrollees. Original Medicare generally covers qualifying SNF care after a hospital admission, but some MA plans apply stricter requirements or deny coverage unless additional conditions are met. This can result in patients being discharged earlier than expected or needing to pursue an appeal to secure coverage.

7. Aggressive marketing practices create challenges for consumers. 
MA plans are heavily promoted by insurers, and marketing efforts have drawn scrutiny for being confusing or overly aggressive. Beneficiaries may receive numerous sales calls, advertisements, or promotional materials, making it challenging to distinguish between marketing claims and the actual benefits offered.