Get Enrolled in Medicare Right the First Time — and Stay Enrolled.
Medicare enrollment decides the first date you can be paid, and a missed revalidation or an unreported change can switch your billing off. MedVersify prepares and files your PECOS applications, answers the MAC’s development requests, sets up reassignments to your group, and tracks every revalidation and reporting deadline afterwards.
- PECOS applications for individuals and groups
- CMS-855I, 855B, 855O, and CMS-588 EFT
- Reassignment of benefits to your group
- MAC development requests answered fast
- Revalidation tracked years ahead
- Changes reported inside the 30- and 90-day windows
Four Medicare Enrollment Numbers Every Practice Should Know
30 days
Maximum Retroactive Billing
Medicare generally lets you bill for services up to 30 days before your enrollment effective date — and only if circumstances prevented you from enrolling sooner. Anything earlier is unpaid.
42 CFR 424.521
5 years
Revalidation Cycle
Physicians, non-physician practitioners, and groups must revalidate their Medicare enrollment every five years (DMEPOS suppliers every three), or billing privileges are deactivated.
42 CFR 424.515
30 / 90
Days to Report Changes
Changes of ownership, adverse legal actions, and practice-location changes must be reported within 30 days. Most other changes have 90 days.
42 CFR 424.516
$750
2026 Application Fee — Institutions Only
Institutional providers pay a $750 Medicare application fee in 2026. Physicians, non-physician practitioners, and physician groups pay no fee.
CMS-6096-N, Federal Register, Dec. 2025
Every Medicare Enrollment Transaction, Handled End to End
Medicare enrollment is one part of our provider credentialing service, which also covers Medicaid, commercial payers, and CAQH. You can use us for Medicare only, or for your whole payer list.
Initial enrollment
New physicians and non-physician practitioners enrolled through PECOS with the CMS-855I, including NPI, licensure, practice location, and specialty details that match what the MAC will verify.
Group and clinic enrollment
New group practices and clinics enrolled with the CMS-855B, including the authorized and delegated officials who will manage the enrollment going forward.
Reassignment of benefits
When a provider joins your group, their right to Medicare payment is reassigned to the group. The separate CMS-855R form has been merged into the CMS-855I, so reassignments now go through the 855I or PECOS.
Ordering & referring enrollment
Providers who only order or refer — labs, imaging, DME, home health — and don’t bill Medicare still need the CMS-855O, or the services they order are denied.
EFT and payment setup
The CMS-588 electronic funds transfer authorization and ERA enrollment, so payments and remittances reach the right account once claims start paying.
Development requests
When the MAC asks for more information, the application can be rejected if you don’t answer within 30 days. We answer these quickly and track them to approval.
Revalidation
We watch CMS’s revalidation due-date list for every provider and group, file on time, and keep billing from being deactivated.
Changes of information
New locations, address changes, ownership changes, and providers leaving the group, all reported inside Medicare’s 30- and 90-day windows.
Opt-out and private contracting
For providers who choose not to bill Medicare at all, we prepare the opt-out affidavit. It lasts two years and renews automatically unless it is cancelled in time.
Which Medicare Enrollment Form You Need
Most enrollments are filed online in PECOS, which uses the same information as the paper CMS-855 forms. Picking the wrong form, or the wrong section of the right one, is a common cause of rejected applications. Use our credentialing timeline estimator to plan your start date.
CMS-855 enrollment forms
| Form | Who files it | Typical use |
|---|---|---|
| CMS-855I | Physicians and non-physician practitioners (NPs, PAs, therapists, psychologists, counselors, and others) | Initial enrollment, revalidation, changes, and reassignment of benefits to a group |
| CMS-855B | Clinics, group practices, and certain other suppliers | Enrolling or revalidating the group itself and its practice locations |
| CMS-855O | Providers who only order, refer, or certify | Ordering labs, imaging, DME, or home health without billing Medicare |
| CMS-855A | Institutional providers (hospitals, home health agencies, hospices, SNFs, and others) | Facility enrollment; the application fee applies |
| CMS-855S | DMEPOS suppliers | Durable medical equipment and supplies; revalidates every three years |
| CMS-588 | Anyone who will be paid by Medicare | Electronic funds transfer authorization |
The CMS-855R reassignment form has been merged into the CMS-855I. Source: CMS Medicare enrollment for providers and suppliers.
Medicare enrollment deadlines that cost money if missed
| Event | Deadline | What happens if you miss it |
|---|---|---|
| Retroactive billing | Up to 30 days before the effective date (90 days after a Presidentially declared disaster) | Services before that window can’t be billed to Medicare |
| Responding to a MAC development request | 30 days | The MAC can reject the application, and you start over |
| Change of ownership, adverse legal action, or practice location | 30 days | Risk of revocation or claims paid to the wrong location |
| Other changes of information | 90 days | Possible deactivation of billing privileges |
| Revalidation | By the due date CMS posts (every 5 years) | Deactivation — no payment for services during the gap |
| Opt-out cancellation | At least 30 days before the 2-year period ends | The opt-out renews automatically for another two years |
Sources: 42 CFR 424.515, 424.516, 424.520, 424.521, and 424.525; CMS opt-out guidance.
Why Medicare Enrollments Get Delayed, Rejected, or Switched Off
Starting to see patients before applying
Your effective date is generally the later of the date the MAC receives an application it can process, or the date you started at the location. With only 30 days of retroactive billing, applying late means working weeks for free.
Data that doesn’t match other records
The name, practice address, licence, and specialty on the application have to match NPPES, the state licensing board, and IRS records. Small mismatches trigger development requests and delays.
Forgetting the reassignment
An individual enrollment alone doesn’t let a group bill for a new provider’s services. The reassignment to the group has to be in place, or claims under the group’s number deny.
Missing the revalidation notice
Revalidation letters go to the correspondence address on file, which is often out of date. CMS also posts due dates publicly, and that list should be checked rather than waiting for mail.
Not reporting a new location
Seeing Medicare patients at a location that isn’t on your enrollment can lead to denials or, in some cases, revocation. New sites need to be added within 30 days.
Assuming Medicare Advantage follows
Medicare enrollment doesn’t put you in network with Medicare Advantage plans. Each plan credentials you separately, which is part of our credentialing service.
How MedVersify Handles Your Medicare Enrollment
Intake and record check
We collect licences, NPI, CAQH data, and practice details, and check them against NPPES and state boards before anything is filed.
Choose the right path
Initial, reassignment, ordering-only, or group enrollment — we pick the right forms and file in PECOS wherever possible.
Plan the effective date
Applications go in early enough that the effective date lines up with the provider’s first day seeing patients.
Answer the MAC fast
Development requests are answered quickly and in full, so the 30-day deadline never becomes a rejection.
Confirm and connect billing
Once approved, the PTAN, effective date, and EFT details go to your billing team so claims can be submitted right away.
Monitor for life
Revalidations, changes, and new locations are tracked for every provider so the enrollment never lapses.
Frequently Asked Questions
How long does Medicare enrollment take?
▾
Can I bill Medicare for patients I saw before my enrollment was approved?
▾
Is there a fee to enroll in Medicare?
▾
What is a reassignment of Medicare benefits?
▾
How often does Medicare revalidation happen?
▾
Can marriage and family therapists and mental health counselors enroll in Medicare?
▾
Does Medicare enrollment make me in-network with Medicare Advantage plans?
▾
Medicare Enrollment Help
Start Billing Medicare on Your First Day — Not Your Third Month.
Tell us who needs to be enrolled and when they start. We’ll map out the forms, the timeline, and the effective date before anything is filed.
Prefer to call? (507) 312-9282Sources
- CMS — Medicare enrollment for providers and suppliers
- CMS — Medicare Learning Network: Medicare provider enrollment
- eCFR — 42 CFR Part 424, Subpart P (provider enrollment)
- Federal Register — CY 2026 Medicare, Medicaid and CHIP application fee (CMS-6096-N)
- CMS — Medicare revalidation list
- CMS — Consolidated CMS-855I bulletin (855R merged into 855I)
Payer rules change often. Figures and deadlines on this page reflect the sources above as of the date they were published — confirm against your payer contract and current CMS guidance before relying on them for a specific claim.