How to Submit Medicare Reimbursement Claims: A Step-by-Step Guide

Estimated read time: ~7 minutes

Summary: Many Medicare claims are submitted by your healthcare provider automatically, but you’ll occasionally need to submit or chase down a reimbursement independently. Knowing who to contact can save you time and frustration.

Suppose you had lab work done at a facility that didn’t bill Medicare directly. By submitting your claim with the correct form and documentation, you may be able to receive reimbursement for Medicare’s share.

While medical offices often bill Medicare directly for covered care, you may occasionally need to file Medicare claims and get paid yourself after a covered medical appointment or purchase. Here’s a closer look at how to submit Medicare reimbursement claims when it wasn’t handled by the provider automatically.

Understanding the basics of Medicare claims

Medicare claims are requests for payment submitted to Medicare after receiving medical services or supplies covered by Medicare Part A or Part B. For Medicare Part C, you’re most likely going to work directly with the Medicare Advantage provider instead.

Typically, healthcare providers file these claims directly, but in certain situations, you may need to file them yourself. This often happens when you receive services from providers who do not accept Medicare assignment. Understanding the claims process helps you receive reimbursements as quickly as possible for covered services and treatments.

How to submit claims to Medicare

We’ve broken down the Medicare reimbursement process into five steps, from gathering documents and submitting a Medicare claim form to receiving payment from Medicare.

Before scheduling an appointment with a new medical provider, it’s a good idea to ask if they accept Medicare and bill Medicare plans directly, which may help you avoid having to submit claims to Medicare from the start.

1. Collect your documents

Before you can complete your Medicare reimbursement form, you’ll need to gather documents from your provider and any other insurance, which may include:

• Itemized bills from your healthcare provider
• Any receipts for past payments you’ve made related to this charge
• Explanation of benefits (EOB) forms from other insurance coverage
• Details of the service (date, place and description of service)
• Doctor’s name, address and Medicare National Provider Identifier (NPI)

These should give you everything needed to complete your forms and submit your Medicare reimbursement request. You have one year from the date of service to submit the claim, but turning it in as soon as possible helps you avoid forgetting about the claim and losing out on the reimbursement.

2. Download and complete the correct form

To file your claim, download and complete the “Patient’s Request for Medical Payment” form (CMS-1490S). You can download the latest version of this form from the official Medicare website.¹

Double-check to ensure you haven’t missed any boxes or made any mistakes. A single mistake can delay your reimbursement or result in a denial for a service or purchase that may otherwise qualify for reimbursement.

3. Attach all required documentation

Gather your completed CMS-1490S and the documentation you put together in step one above. Make a copy of all files and mail the copies (not the original documents) to the Medicare contractor listed at the bottom of the CMS-1490S.

Ensure each document clearly shows your name, the provider’s details, the service date and itemized charges.

4. Mail the claim

Now it’s time to drop your forms in the mailbox. Send your completed form and attached documentation to the appropriate Medicare Administrative Contractor (MAC). You must file your claim within 12 months of the date when you received covered services in most situations.²

Addresses vary based on your state, so verify your MAC’s current mailing address with Medicare, either from the bottom of the Patient’s Request for Medical Payment or on the Medicare website. Medicare is a common target for fraud, so ensure you trust only a .gov website when confirming the address.

5. Follow up and check the status

After submitting your claim, you can check its status through your account at Medicare.gov or by calling Medicare directly at 1-800-MEDICARE. Staying proactive helps address any issues promptly. You can usually see your claim in your Medicare.gov account within 24 hours after Medicare receives and processes the claim form.

The processing begins once Medicare receives your claim. Medicare typically reimburses 80% of the Medicare-approved amount for covered services under Part B after deductibles are met. It takes approximately 30 days to process claims, barring any errors or complications.³

Along the way, you may receive a Medicare Summary Notice (MSN). It’s a notice to those insured by Medicare sent every four months to explain their Medicare Part A and Part B benefits. When your claim is processed, you should be able to find a record in your next MSN.

The Medicare reimbursement process

Once you send in your forms, Medicare takes the following steps to process your claim:

1. Medicare reviews the submitted documents.
2. It approves or denies the claim based on coverage rules.
3. It sends payment directly to the healthcare provider or issues reimbursement to you, depending on the claim and whether the provider accepts Medicare assignment.

Keep an eye out for your regular Medicare Summary Notice for confirmation the claim or reimbursement has been processed successfully.

How Medicare supplement insurance claims are paid

Medicare supplement insurance policies help with out-of-pocket costs after Original Medicare processes a claim. Medicare pays its approved portion first, after which any remaining eligible charges are submitted to the Medicare supplement insurance carrier for review and potential payment.

You usually do not need to file a separate claim for Medicare supplement insurance. Providers or Medicare directly forward claims to your Medicare supplement insurer automatically. If your claim isn’t handled automatically, reach out to your Medicare supplement insurance provider to ensure it was received. If they don’t have it, you can work backwards from there to ensure they receive the proper Medicare claim information.

Common reasons Medicare claims are denied

While many Medicare claims are processed and paid smoothly, some are still denied. Knowing why denials happen can help you avoid issues and keep your claims on track. Some of the most common causes include:

• Duplicate service
• Non-covered service due to medical necessity
• Already paid with another service
• Incorrect service, procedure, or treatment code submitted
• Provider not certified by Medicare or eligible to perform the service
• Incomplete form
• Missing documentation
• Service not covered by Medicare
• Filing past the one year deadline (unless exceptions apply)
• Billing errors

This is just a snapshot of potential reasons for claim denials.⁴ Ensuring you only work with approved medical care providers and avoid non-covered services can help keep your out-of-pocket costs under control. You can check this database for Medicare providers in different locations.

What to do if your claim is denied

If your claim is denied and you disagree with the reasoning, you can file an appeal with Medicare. While there’s no guarantee, it can be worth the effort.

To appeal a Medicare denial, review your latest MSN and complete the “Redetermination Request” form (Form CMS-20027), explaining why you believe the claim should be covered. Send it, along with any supporting documents, to the address listed on your notice within 120 days of receiving the denial.⁴

Before submitting an appeal, you may need additional documentation from your medical provider. If you need extra help handling a claim denial, consider a trusted family member or friend, whom you can also appoint as your representative, or you can find a local State Health Insurance Assistance Program (SHIP), a free program offering personalized health insurance counseling.

Tips to ensure smooth Medicare reimbursement processing

To avoid problems, the best strategy is to prepare and file your claim forms carefully. These additional tips may help increase the likelihood of a successful claim on the first attempt:

• Confirm the provider accepts Medicare assignment—if they do, Medicare usually pays the provider directly, so you won’t need to submit a claim.
• Maintain organized and detailed medical records.
• Double-check forms and documents before submitting claims.
• Submit claims promptly (within the 12-month deadline) and follow up quickly if necessary.

Filing claims with Mutual of Omaha Medicare supplement: What you should know

For those who have Medicare supplement insurance policies from Mutual of Omaha or an affiliate, here’s how the claims process typically works. After Medicare processes your claim, it automatically forwards details to Mutual of Omaha (and its affiliate companies). Typically, you don’t need to file a separate claim unless there’s an issue or delay.

How to track your Medicare supplement claim with Mutual of Omaha

You can track your claims online via Mutual of Omaha’s customer portal: Customer Access. Simply log into your account to see the real-time status of submitted claims or call Mutual of Omaha’s customer service directly for detailed updates.

You can view all Mutual of Omaha insurance claims and reach customer support using the portal, including options for managing policies, claims and customer service needs. You can also get a copy of your Medicare supplement ID card, view explanation of benefits (EOB) statements, manage paperless settings and handle other account needs through the convenient online portal.

Frequently Asked Questions

Q1: How long does it take Medicare to process a claim?

Most claims are processed within 30 days, though complex cases may require additional time. If a service or product isn’t covered by Medicare, the claim will be denied.

Q2: Who is responsible for filing Medicare claims?

Most of the time, healthcare providers submit claims directly to Medicare. However, you must file your own claim if the provider does not accept Medicare assignment.

Q3: Can I file Medicare claims online?

No, Medicare currently does not offer an online filing option for beneficiaries; claims must be submitted by mail. You can find the form online, but submission requires sending in a paper version of the claim form.

Q4: How can I submit a claim to Medicare?

To submit a claim to Medicare, complete the “Patient’s Request for Medical Payment” form (CMS-1490S), attach supporting documentation and mail it to your Medicare Administrative Contractor.

Q5: Can I submit claims directly to Medicare?

You should use the “Patient’s Request for Medical Payment” form (CMS-1490S) to file claims directly. Medical providers typically submit claims to Medicare directly, so you’ll need to submit a claim only if there’s an issue.

Q6: What do I do if Medicare denies my claim?

If Medicare denies your claim, you don’t necessarily have to pay. You can appeal the decision by completing the Medicare Redetermination Request Form (CMS-20027) within 120 days, along with any supporting documentation.

Sources

¹ Center for Medicare & Medicaid Services. PDF: PATIENT’S REQUEST FOR MEDICAL PAYMENT. Retrieved Jul. 15, 2025 from www.cms.gov/medicare/cms-forms/cms-forms/downloads/cms1490s-english.pdf

² Medicare.gov. Web page: Filing a Claim. Retrieved Jul. 15, 2025 from www.medicare.gov/providers-services/claims-appeals-complaints/claims

³ Centers for Medicare & Medicaid Services. PDF: MLN Matters. Retrieved Jul. 15, 2025 from www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/downloads/MM3557.pdf

⁴ Medicare.gov. PDF publication: Medicare Appeals. Retrieved Sep. 22, 2025 from www.medicare.gov/publications/11525-medicare-appeals.pdf

Insurance products and services are offered by Mutual of Omaha Insurance Company or one of its affiliates. Mutual of Omaha Plaza, Omaha, NE 68175. Products not available in all states.

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