Medicare enrollment through PECOS: timelines and retroactive billing

How Medicare enrollment works

To bill Medicare Part B, physicians, non-physician practitioners and the groups they work for must be enrolled in the Medicare program. Enrollment is handled through PECOS, the Provider Enrollment, Chain and Ownership System, or by paper application. Applications are processed by the Medicare Administrative Contractor (MAC) responsible for the state where services are delivered.

Online filing through PECOS is generally faster and easier to track than paper. It also lets practices see application status, respond to development requests and keep enrollment information updated in one place.

Which applications you need

Most new providers joining a group need more than one piece of the puzzle: their own individual enrollment, the group's enrollment, and a reassignment that allows the group to bill and receive payment for the provider's services.

• Individual physicians and non-physician practitioners: CMS-855I.
• Clinics and group practices: CMS-855B.
• Reassignment of benefits from the individual to the group: completed as part of the enrollment filing.
• Providers who only order or refer services, without billing: CMS-855O.
• Electronic funds transfer authorization: CMS-588, since Medicare pays electronically.

Typical timelines

Medicare enrollment through PECOS commonly takes 60 to 90 days from submission to approval, depending on the MAC, the time of year and how complete the application is. Clean online applications can be faster. Applications that trigger development requests, where the contractor asks for corrections or additional documentation, take longer.

Development requests usually carry a response deadline, often 30 days. Missing that deadline can lead the contractor to reject the application, which means starting over with a new filing date. Rejection is one of the most expensive outcomes in Medicare enrollment because it moves the date that controls retroactive billing.

The effective date rule

For physicians and non-physician practitioners, the effective date of Medicare billing privileges is generally the later of two dates: the date of filing an application that the contractor subsequently approves, or the date the provider first began furnishing services at a new practice location (42 CFR 424.520(d)).

The filing date is the date the contractor receives an application that it is able to process to approval. An application that is later rejected does not preserve its original filing date.

Limited retroactive billing

Under 42 CFR 424.521, eligible physicians, non-physician practitioners and their groups may retrospectively bill for services delivered up to 30 days before the effective date, when circumstances precluded enrollment in advance. In a declared disaster or emergency, that window can extend to 90 days. Services delivered outside the window are not billable to Medicare.

That is more generous than most commercial payers, but it is still narrow. A provider who starts seeing Medicare patients in January and files in April cannot recover January and February. The practical lesson is simple: file as early as you can, and file correctly the first time so the filing date is not pushed back by a rejection.

Revalidation every five years

Most Medicare providers and suppliers must revalidate their enrollment every five years (42 CFR 424.515); durable medical equipment suppliers revalidate every three years. CMS may also request off-cycle revalidation. Revalidation due dates are published by CMS and are typically visible about six months before they arrive.

Missing a revalidation deadline can lead to a hold on payments and deactivation of billing privileges. Reactivation is possible, but it can create a gap in coverage during which claims are not payable. Tracking revalidation dates for every provider and group is far cheaper than recovering from a lapse.

Reporting changes on time

Enrollment is not a one-time event. Medicare requires providers to report certain changes within specific timeframes. Physicians and non-physician practitioners generally must report a change of ownership, an adverse legal action or a change in practice location within 30 days, and other changes within 90 days.

• New or closed practice locations.
• Changes in group affiliation or reassignment.
• Changes to legal name, tax ID or ownership.
• Adverse legal actions, such as license restrictions or exclusions.
• Changes to banking information for electronic payments.

Application fees and screening

Institutional providers and suppliers generally pay a Medicare application fee, which CMS adjusts each year. Individual physicians and non-physician practitioners enrolling on the CMS-855I are not subject to that fee. Groups enrolling on the CMS-855B should confirm whether the fee applies to their organization type.

CMS screens applicants according to risk categories. Most physician and practitioner enrollments fall in the limited-risk category, which involves verification of licensure and checks against federal databases. Higher-risk categories may involve site visits and fingerprint-based background checks.

Common reasons Medicare applications stall

Medicare is rule-driven, which makes most problems predictable.

• Legal names and addresses that do not match NPPES or IRS records exactly.
• A practice location that is a mailbox or virtual office rather than a physical site.
• Missing or unsigned certification statements from the provider or authorized official.
• Incorrect specialty selection for the provider's license and taxonomy.
• Banking information that does not match the enrolling entity's legal name and tax ID.
• Development requests answered late or incompletely.

Opting out instead of enrolling

Some physicians and practitioners choose to opt out of Medicare entirely and contract privately with Medicare patients. Opt-out is a formal process with its own rules, and it lasts for two-year periods that renew automatically unless cancelled. It is a significant decision for any practice that sees older adults and should be made deliberately rather than by default.

A practical Medicare checklist

• Confirm the individual NPI and taxonomy on NPPES are current.
• Confirm the group's legal name, tax ID and practice locations match IRS and NPPES records.
• Decide which applications are needed: individual, group, reassignment, ordering and referring.
• File online through PECOS as soon as the provider's start date is known.
• Answer development requests within days, not at the deadline.
• Record the filing date, approval date, effective date and PTAN for each provider.
• Put revalidation dates and change-reporting rules on the practice calendar.