Quick Answer
In most cases, your doctor or provider files Medicare claims on your behalf. However, if a provider refuses to file or you paid out of pocket, you can submit Form CMS-1490S to request reimbursement within 12 months of service.
Coverage Comparison by Plan Type
| Plan Type | Coverage | Notes |
|---|---|---|
| Original Medicare (Part A & B) | Provider files claims; you file CMS-1490S if they refuse | Claims must be filed within 12 months of service |
| Medicare Advantage (Part C) | In-network providers file directly; out-of-network may require you to file | Contact your plan for specific claim submission instructions |
| Part D (Prescription Drugs) | Pharmacy files automatically; manual claims for out-of-network or new drugs | May need to file if drug not yet on formulary |
| Medigap | Processes automatically after Medicare pays its share | No separate claim needed - crossover claim is automatic |
Understanding Your Coverage Options
When You Need to File a Claim
By law, Medicare-enrolled providers must file claims on your behalf. You should only need to file a claim yourself in rare situations.
You may need to file if your provider refuses to submit a claim, isn't enrolled in Medicare, or you received care outside the U.S. in limited qualifying situations.
What It Covers
- Provider refuses or is unable to file the claim
- Provider isn't enrolled in Medicare
- You paid out of pocket and need reimbursement
- Certain emergency services received abroad
What It Doesn't Cover
- Services not covered by Medicare (cosmetic, routine dental, etc.)
- Claims filed after the 12-month deadline
- Services from providers who have opted out of Medicare
Important
If your provider hasn't filed a claim, contact them first. Only file yourself if they refuse or are unable to submit it.
How to File Form CMS-1490S
The Patient's Request for Medical Payment (CMS-1490S) is the official form for beneficiaries to request reimbursement from Medicare.
Download the form from CMS.gov, complete all required fields, attach your itemized bill, and mail it to your state's Medicare Administrative Contractor (MAC) address listed on the form.
What It Covers
- Completed CMS-1490S form (available in English and Spanish)
- Itemized bill from your provider showing services and charges
- Letter explaining why you're submitting the claim
- Any supporting documents (doctor's notes, referrals)
What It Doesn't Cover
- Claims without an itemized bill will not be processed
- Incomplete forms will be returned
- Electronic submission is not available for beneficiaries
Pro Tip
Keep copies of everything you submit. Mail your claim via certified mail so you have proof of the submission date.
Assignment vs. Non-Assignment
When a provider 'accepts assignment,' they agree to accept Medicare's approved amount as full payment. You only owe your deductible and 20% coinsurance.
Non-participating providers who don't accept assignment can charge up to 15% above the Medicare-approved amount (called excess charges). You pay the difference plus your coinsurance.
What It Covers
- Participating providers always accept assignment
- Non-participating providers may accept on a case-by-case basis
- Limiting charge caps excess at 15% above approved amount
What It Doesn't Cover
- Opt-out providers don't file Medicare claims at all
- You pay full cost with opt-out providers (private contract)
- Medicare won't reimburse for opt-out provider services
Medicare Advantage Reimbursement
If you have a Medicare Advantage plan, in-network providers file claims directly with your plan. Out-of-network services may require you to pay upfront and request reimbursement from your plan.
Contact your MA plan directly for their specific claim forms and submission process. Each plan has its own procedures and timelines.
What It Covers
- In-network providers file claims automatically
- Emergency services covered regardless of network
- Out-of-network reimbursement if plan allows
What It Doesn't Cover
- Out-of-network non-emergency services (HMO plans)
- Services requiring prior authorization that wasn't obtained
- Claims filed after plan-specific deadline
Medicare Reimbursement Amounts by Provider Type
| Provider Type | What Medicare Pays | What You Pay |
|---|---|---|
| Participating (accepts assignment) | 80% of approved amount | 20% coinsurance + deductible |
| Non-participating (doesn't accept assignment) | 80% of approved amount (paid to you) | 20% coinsurance + up to 15% excess charge |
| Opt-out provider (private contract) | $0 - Medicare does not pay | 100% of provider's charges |
| Foreign provider (qualifying emergency) | 80% of approved amount (limited situations) | 20% coinsurance + deductible |
✦ Important Exceptions & Special Situations
12-Month Filing Deadline
Medicare claims must be filed within 12 months (one full calendar year) after the date of service. If the deadline passes, Medicare will not pay regardless of the reason.
No exceptions to the 12-month filing deadline for standard claims.
Foreign Emergency Care
Medicare generally doesn't cover care outside the U.S. However, it may cover emergency hospital care in limited situations: within the U.S. when a foreign hospital is closer, on a ship within 6 hours of a U.S. port, or traveling through Canada between Alaska and another state.
Retroactive Medicare Coverage
If you receive retroactive Medicare coverage, you can file claims for services received during the retroactive period even if the 12-month window from the service date has passed.
Medicare Secondary Payer
If another insurer (employer plan, auto insurance, workers' comp) is primary, Medicare may reimburse you for amounts it should have paid once the primary payer settles.
✦ Recent Policy Updates
2025 Physician Fee Schedule Update
PassedCMS updated Medicare reimbursement rates with a 2.93% reduction in the conversion factor for 2025, affecting how much Medicare pays providers for services.
Electronic Claims Submission for Beneficiaries
ProposedCMS is exploring options to allow beneficiaries to submit claims electronically rather than by mail, which would speed up reimbursement processing.
Tips for Getting Reimbursed Faster
While Medicare claims processing typically takes 30 days, you can take steps to avoid delays and ensure your reimbursement is processed smoothly.
Reimbursement Checklist
- Always ask if your provider accepts Medicare assignment before receiving services
- Request an itemized bill immediately after paying out of pocket
- Download Form CMS-1490S from CMS.gov and complete all fields
- Include a clear explanation letter with your claim submission
- Mail via certified mail and keep copies of everything
- Check your Medicare Summary Notice (MSN) to confirm claim was processed
- Contact 1-800-MEDICARE if your claim hasn't been processed within 60 days
✦ Frequently Asked Questions
David Haass
AuthorDavid Haass is a licensed insurance agent and Medicare specialist at MedicareFAQ.com.
Ashlee Zareczny
ReviewerAshlee Zareczny is the Compliance & Editorial Manager at MedicareFAQ.