What PECOS Medicare Is and How It Affects Your Coverage

PECOS is the federal database that tracks which doctors and suppliers are allowed to bill Medicare

PECOS stands for Provider Enrollment, Credentials, and Other Information System. It is the official list maintained by the Centers for Medicare & Medicaid Services (CMS) that shows which doctors, hospitals, therapists, medical equipment suppliers, and other healthcare providers are authorized to treat Medicare patients and submit bills to Medicare.

When you see a doctor or use a supplier, that provider must be enrolled in PECOS for Medicare to pay the claim. If a provider is not in PECOS, Medicare will deny the bill, and you may be responsible for the full cost. This affects which providers you can see without risking unexpected bills.

PECOS is not a choice you make. It is a requirement that providers meet before they can work with Medicare at all. Understanding what PECOS is helps you know why some providers can bill Medicare and others cannot, and what to do if you suspect a provider is not properly enrolled.

Key Takeaways

• PECOS is the CMS database that lists all providers authorized to bill Medicare; if a provider is not in PECOS, Medicare will not pay their bills.
• You can search PECOS yourself online to confirm a doctor, hospital, or supplier is enrolled before you schedule an appointment.
• Providers must renew their PECOS enrollment every five years, and enrollment can be revoked if a provider breaks Medicare rules.
• If a provider bills you for a service they were not enrolled to provide, you may have the right to refuse payment and report them to CMS.
• PECOS enrollment does not mean a provider accepts Medicare; some enrolled providers do not take Medicare patients, so you still need to confirm directly.

How PECOS enrollment works and why it matters to you

Before any healthcare provider can bill Medicare, they must complete an enrollment process with CMS and be added to PECOS. This includes doctors, nurse practitioners, physician assistants, hospitals, home health agencies, dialysis centers, durable medical equipment suppliers, and many other types of providers.

The enrollment process requires providers to submit detailed information: their credentials, malpractice history, ownership structure, and whether they have been excluded from federal programs. CMS reviews this information to make sure the provider is legitimate and has not been barred from Medicare for fraud, abuse, or other violations.

For you, this means that PECOS is a safety mechanism. Providers in PECOS have been vetted by CMS. If a provider is not in PECOS, Medicare cannot pay them, which protects the program from paying fraudulent or unqualified providers. It also protects you, because you know that any provider in PECOS has at least passed a basic enrollment check.

How to check if a provider is enrolled in PECOS

You can search PECOS yourself at no cost using the CMS Provider Enrollment, Credentials, and Other Information System (PECOS) online tool. Go to the CMS website, find the PECOS search page, and enter the provider's name, National Provider Identifier (NPI), or location. The search will tell you whether the provider is currently enrolled.

When you search, you will see the provider's enrollment status, the date they enrolled, and the types of services they are authorized to provide. Some providers are enrolled for specific services only — for example, a therapist might be enrolled to provide physical therapy but not occupational therapy.

If a provider you plan to see does not appear in PECOS, contact them directly and ask whether they are enrolled. They may be newly enrolled and not yet in the database, or they may not accept Medicare at all. Do not assume a provider accepts Medicare just because they are in your insurance network; PECOS enrollment and network status are separate things.

What happens if a provider is not enrolled in PECOS

If you receive care from a provider who is not enrolled in PECOS, Medicare will not pay the bill. The provider may bill you directly for the full cost of the service. You are not responsible for paying a bill for a service you did not know the provider was not enrolled to provide, but proving that can be difficult.

If a provider knowingly bills Medicare for services they are not enrolled to provide, that is fraud. If you believe this has happened, you can report it to the CMS Office of Inspector General (OIG) or call the Medicare fraud hotline. Keep copies of all bills and correspondence.

To protect yourself, check PECOS before you schedule an appointment, especially if you are seeing a new provider or a specialist. If you have already received a bill from an unenrolled provider, contact Medicare directly to ask whether the claim was denied and what your responsibility is.

PECOS enrollment renewal and when providers lose their status

Providers must renew their PECOS enrollment every five years. If a provider does not renew on time, their enrollment is deactivated and they can no longer bill Medicare. Some providers choose not to renew if they are retiring or changing their practice.

CMS can also revoke a provider's PECOS enrollment if they violate Medicare rules, commit fraud, have unresolved billing disputes, or are convicted of certain crimes. When this happens, the provider is removed from PECOS and cannot bill Medicare going forward. In serious cases, a provider may be excluded from all federal healthcare programs.

If your regular provider suddenly stops appearing in PECOS, contact their office to ask why. They may be in the middle of renewing, or there may be a problem you should know about. Do not assume the provider is still authorized to bill Medicare.

The difference between PECOS enrollment and accepting Medicare

Being enrolled in PECOS does not mean a provider accepts Medicare patients. Some providers are enrolled but do not take Medicare. Others are enrolled but only see Medicare patients under certain conditions — for example, only in a hospital setting, or only for specific diagnoses.

When you call a provider's office to schedule an appointment, always ask directly whether they accept your Medicare plan. Do not rely on PECOS enrollment status alone. A provider can be in PECOS and still refuse to see you as a Medicare patient.

Some providers are enrolled in PECOS but have opted out of Medicare entirely. These providers can still bill Medicare in emergencies, but they choose not to participate in the program. If you see an opted-out provider, you will likely have to pay out of pocket.

What to do if you receive a bill from an unenrolled provider

If you receive a bill for a service and you suspect the provider was not enrolled in PECOS at the time they provided the service, take these steps. First, search PECOS to confirm the provider's current status. Second, contact your Medicare plan or Original Medicare to ask whether the claim was submitted and whether it was denied.

If the claim was denied because the provider was not enrolled, you should not be responsible for the bill. Contact the provider's billing office and explain that the claim was denied due to lack of PECOS enrollment. Ask them to write off the balance or resubmit once they are enrolled.

If the provider insists you owe the money, you can file a complaint with your state's medical board or with CMS. Keep all documentation: the bill, the date of service, your Medicare Explanation of Benefits, and any correspondence with the provider.

Frequently Asked Questions

Can I see a provider who is not in PECOS?

Yes, but Medicare will not pay the bill. You will be responsible for the full cost. Before you schedule an appointment, search PECOS to confirm the provider is enrolled, or call their office and ask directly whether they accept Medicare.

Does PECOS enrollment mean the provider is good or trustworthy?

PECOS enrollment means the provider has passed a basic background check and credential review by CMS. It does not may provide quality of care or that the provider is the right fit for you. Check reviews, ask for referrals, and verify the provider's specialty and experience separately.

What is an NPI and why do I need it to search PECOS?

An NPI is a National Provider Identifier — a unique 10-digit number assigned to every healthcare provider. You can find a provider's NPI on your insurance card, on their website, or by calling their office. Using the NPI makes your PECOS search faster and more accurate than searching by name alone.

If a provider is enrolled in PECOS, do they have to accept my Medicare plan?

No. PECOS enrollment means they are authorized to bill Medicare, but they may not accept your specific plan, may not be taking new patients, or may have other restrictions. Always call the provider directly to confirm they accept your plan before scheduling.

What happens if I already paid a bill from an unenrolled provider?

Contact the provider and explain that they were not enrolled in PECOS at the time of service. Ask for a refund. If they refuse, file a complaint with CMS or your state's medical board. Keep all receipts and documentation of your payment.