Medicare patients whose doctor, lab or supplier never sent a bill to Medicare have 12 months from the date of service to file the claim themselves on Form CMS-1490S. Medicare.gov says claims “must be filed no later than 12 months (or 1 full calendar year) after the date when the services were provided unless an exception applies.” After that, Medicare will not pay its share, and whatever the patient paid out of pocket stays paid.
The rule falls hardest on patients who paid a provider directly and assumed a claim followed. A visit on Dec. 2, 2025, has to be on file by Dec. 2, 2026. Months of silence after the payment can use up the clock without a single letter from Medicare to warn about it.
Who has to file a Medicare claim
Most patients never file anything. Medicare.gov says Original Medicare providers are required by law to file claims, and Medicare drug plans and in-network Medicare Advantage providers usually submit claims for the patient. The patient’s own claim is the fallback, for cases where a provider “refused to submit a claim” and the patient paid out of pocket.
The same page says that when a provider has not filed and the deadline is near, “you should file the claim.” In other words, a patient does not have to win an argument with the provider first. Once the 12 months are close to running out, the safer move is to send the form.
Anyone who paid a provider directly and never saw that visit on a Medicare Summary Notice should do three things in order: find the date of service on the receipt, look up whether Medicare has the claim on the claim status page, and, if it does not, count how many months remain before the 12-month date.
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What goes in the envelope
The form is the Patient Request for Medical Payment. The CMS-1490S instructions say beneficiaries can use it when a provider or supplier refuses or is unable to file a claim, or is not enrolled with Medicare. The patient checks one reason box and one request-type box, and the types include Part B services, flu and pneumococcal shots, durable medical equipment, foreign travel and shipboard services.
An itemized bill has to go with it. The instructions list the date and place of service, a description of the illness or injury, each service or supply with its charge, and the provider’s name and address, plus the provider’s National Provider Identifier if known. Medicare.gov adds a letter explaining why the patient is filing and any supporting papers, such as notes from the doctor.
Patients asking Medicare to pay second, after another insurer, add a copy of that insurer’s Explanation of Benefits. The form tells patients to keep a copy of everything they send and to mark out any services already claimed on the bill. Filing early leaves room to fix a missing attachment before the 12 months run out.
The mailing address depends on the state. Medicare.gov says original Medicare claims go to the Medicare Administrative Contractor listed for the patient’s state in the address table that comes with the form. The instructions warn against sending it to the CMS paperwork clearance address, which delays processing, and say to allow at least 60 days for Medicare to receive and process the request.
What this form cannot do
Some bills cannot be recovered this way even when filed on time. The form says Medicare will not process beneficiary requests for diabetic test strips, Part B drugs, or items paid under the competitive bidding program for durable medical equipment. A patient who paid for one of those needs a different route, and a call to Medicare is the place to ask which.
Care outside the country is another narrow lane. Medicare generally does not pay for health care services furnished outside the United States, and the form lists only three limited exceptions, such as certain emergencies or a foreign hospital that is closer to home than a U.S. hospital. Foreign travel claims go to the Medicare contractor for the patient’s state of residence.
When the 12 months can stretch
The federal regulation behind the rule, 42 CFR 424.44, says that for services on or after Jan. 1, 2010, a claim must be filed no later than the close of the period ending one calendar year after the date of service. If that last day falls on a federal nonworkday, the deadline moves to the next workday.
Two exceptions matter to patients. The deadline is extended if Medicare or a contractor finds the miss was caused by error or misrepresentation by a Medicare employee, contractor or agent, and the extension runs through the sixth calendar month after the correction notice. It does not apply to requests made more than four years after the service date.
The other exception covers retroactive Medicare entitlement. A person who was not entitled to Medicare when care was given but later received retroactive entitlement may get an extended deadline. These are narrow rules, and Medicare.gov’s claims page does not list them, so patients who think one applies should ask before assuming it does.
Help is available. Medicare.gov points patients to the State Health Insurance Assistance Program for local counselors, and to 1-800-MEDICARE at 1-800-633-4227 or live chat on Medicare.gov. A counselor can read an itemized bill alongside the patient and confirm the state address before the envelope goes out.
Paid a provider that never billed Medicare?
The 12 months run from the date of service, not from the day the patient noticed. A claim that reaches Medicare after that date draws no payment, so the cost of waiting is the whole share Medicare would have covered.
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This article was produced with AI assistance and edited for accuracy against the sources linked above.
