Medicare Advantage Plan Paid You Less Than Medicare? How Non-Contracted Providers Dispute It

If you have no contract with the Medicare Advantage plan, you must accept as payment in full what you could have collected under Original Medicare (42 CFR 422.214(a)(1)), and CMS requires plans to pay non-contracted providers that amount. If the plan paid less, file the plan's non-contracted provider payment dispute inside its window, often 120 days from the initial determination. Check the plan's own form for the exact window. If the plan upholds the underpayment, request an independent decision from CMS's Payment Dispute Resolution Contractor.

In 2026, 55% of eligible Medicare beneficiaries, 35.2 million of 64.2 million people with both Part A and Part B, are enrolled in Medicare Advantage, according to KFF's 2026 enrollment update. That share was 19% in 2007. More than half of the Medicare patients in an independent practice's schedule now carry a private plan card, not a red-white-and-blue one.

No practice contracts with every plan. Plans differ by county, by product (HMO, PPO, special needs plans), and by year, and a practice contracted under one plan's HMO can still be non-contracted for the same company's PPO. So out-of-network Medicare Advantage claims are routine, not rare.

Those claims are also where underpayments hide. The remittance shows a payment, so the claim looks closed. Nobody compares the amount to what Original Medicare would have paid, and the gap is adjusted off as if it were a contractual write-off, when there is no contract behind it.

The amount

The rule sits in 42 CFR 422.214(a)(1): a provider without a contract "must accept, as payment in full, the amounts that the provider could collect if the beneficiary were enrolled in original Medicare." In practice that means the Original Medicare allowed amount for the service, at your locality, split between the plan's payment and the patient's cost sharing. CMS's MA Payment Guide for Out of Network Payments puts it the same way: combined plan payment and member cost sharing of at least what Original Medicare would have paid.

The patient

You can't balance bill the patient above that amount. The patient owes their plan cost sharing and nothing more. So when the plan's share comes in short, the underpayment is the plan's to fix, not the patient's.

Timing

42 CFR 422.520(a) sets the prompt payment rules for claims not furnished under a written agreement with the plan:

• The plan must pay 95% of clean claims within 30 days of receipt.
• The plan must pay interest on clean claims not paid within 30 days.
• All other claims from non-contracted providers must be paid or denied within 60 calendar days from the date of the request.

A late payment and a short payment are separate problems. A plan can pay on time and still pay the wrong amount.

The first job is to pick the right route. Sending a short payment through the appeal process, or a denial through the payment dispute process, costs weeks and can cost the window. CMS's payment dispute process manual sets out which decisions belong where.

The manual is direct about the last row: a contracted provider "may not request an independent payment dispute decision since these disputes are considered to be matters of contract disputes." Contract status is per plan product, so confirm it for the exact plan on the patient's card before choosing a route.

The dispute stands or falls on one number: what Original Medicare would have paid. Build that first, then use the plan's process, then CMS's.

1. 01

   Price the claim as Original Medicare would

   Use the CMS Physician Fee Schedule Look-Up Tool for your locality, the date of service year, and the same codes and modifiers you billed. Note whether you are a participating or non-participating Medicare provider, since that changes the Original Medicare amount. Write the calculation down line by line. It becomes your evidence.

2. 02

   Check that the gap isn't a legitimate reduction

   Original Medicare reduces payment too. Multiple procedure reductions, assistant-at-surgery rates, the facility rate when the service was in a hospital setting, and bilateral rules all lower the allowed amount. Apply them to your own calculation before disputing. If the plan's payment matches Original Medicare after those reductions, there is no underpayment.

3. 03

   File the plan's non-contracted provider payment dispute

   File inside the plan's window, with the claim, the plan's remittance and your fee schedule calculation. The window and the response time are set by each plan. One example: Health Net's Wellcare policy asks for disputes within 120 days of the initial payment decision and says it responds within 30 days. Use the plan's own form where it has one.

4. 04

   If the plan upholds it, request CMS's independent decision

   Submit CMS's Payment Dispute Decision request. Per the process manual, the request asks for the original claim, the plan's remittance and the plan's dispute decision, along with pricing details such as NPI, ZIP code of service and the plan's name. Older documents name both First Coast and C2C as the contractor. Confirm the current contractor and submission address on cms.gov before you send anything.

5. 05

   Track each deadline per claim

   Every disputed claim carries its own clock: the plan's dispute window from the initial determination, then the plan's response, then the CMS request. A spreadsheet works if someone owns it. Before any batch, check each claim's window.

Underpayments are rarely one claim. A plan that pays one code short usually pays every instance of it short. If you find the pattern, work MA underpayments with the rest of your AR.

Sources last checked: 15 Oct 2026