Revised CMS-855B Is Now Mandatory: What Changed and What Groups Must Do

What Changed on the Revised CMS-855B Form?

As of August 3, 2026, Medicare Administrative Contractors only accept the revised version of the CMS-855B enrollment application for clinics, group practices, and certain other suppliers. The updated form adds Section 4H for reporting reassignment of benefits directly on the 855B, Section 15E for the individual practitioner’s signature, and a new submittal reason in Section 1A for providers enrolling in Medicare solely to participate in Medicaid or another health care program. Any group submitting the old version of the form after August 3 receives an automatic return, adding 30 to 60 days to their enrollment timeline.

• Reassignment on the 855B: Groups can now report reassignment information directly on the 855B instead of filing a separate form for each practitioner.
• Medicaid-only enrollment path: Section 1A now includes a submittal reason for providers who enroll in Medicare solely to satisfy Medicaid or CHIP program requirements.
• Old forms rejected: MACs accepted both old and revised versions through August 2, 2026. Starting August 3, only the revised form is processed.

The Revised 855B Form Explained

CMS revised the CMS-855B, the Medicare enrollment application used by clinics, group practices, and certain other suppliers, with an official revision date of April 29, 2026 listed on the CMS forms page. The biggest structural change is how reassignment of benefits is handled. Previously, when a group practice needed to report that an individual practitioner was reassigning Medicare billing rights to the group, the process required filing a separate CMS-855R form for each practitioner. That standalone 855R form has already been consolidated into the CMS-855I for individual practitioners. Now, the revised 855B brings the group’s side of the reassignment into the same application.

Section 4H of the revised 855B allows the group to identify the individual practitioner who is reassigning benefits. Section 15E provides a signature block for that practitioner. If the group is accepting reassignments from more than one provider, they submit separate Section 4H and Section 15E pages for each individual, along with the appropriate authorized or delegated official signatures. This consolidation reduces the total number of forms in play during a group enrollment and keeps the reassignment data inside the same application the MAC is already processing.

The second significant change is the new submittal reason in Section 1A. This option is designed for providers who intend to enroll in Medicare solely to participate in Medicaid or another health care program and do not intend to bill Medicare for services. This path exists because many state Medicaid programs and managed care plans require an active Medicare enrollment as a prerequisite for Medicaid participation, even if the provider will never submit a Medicare claim.

Who Is Affected by the CMS-855B Revision?

The revised form applies to every entity that uses the CMS-855B for Medicare enrollment. This includes group practices, clinics, ambulatory surgical centers, independent clinical laboratories, portable X-ray suppliers, mammography screening centers, radiation therapy centers, and other Part B institutional suppliers. Solo practitioners who file under the CMS-855I are not directly affected by the 855B revision, though the parallel changes to the 855I that consolidated the 855R are already in effect.

The groups most likely to encounter problems are those that still file paper CMS-855 applications. PECOS, the online enrollment system, has already been updated to reflect the revised form structure. Groups that submit electronically through PECOS may not even notice the change, since the system walks applicants through the current fields. The disruption hits practices that download the PDF from the CMS website, print it, complete it by hand or typewriter, and mail it to their MAC.

In our experience filing Medicare enrollments across 40+ states, the paper workflow is still common among smaller group practices, particularly those without dedicated credentialing staff. These are the practices most at risk of submitting the outdated form and receiving an automatic return.

Why CMS Made These Changes Now

The 855B revision is part of a broader CMS initiative to streamline enrollment forms and reduce the number of standalone applications in the Medicare enrollment ecosystem. CMS had already merged the CMS-855R into the CMS-855I, eliminating the standalone reassignment form for individual practitioners filing on paper. The 855B update brings the group side of that same transaction into the group’s own application, completing the consolidation.

The timing aligns with CMS’s escalating program integrity enforcement. The CY 2027 Home Health PPS proposed rule, published July 6, 2026 with comments due August 31, proposes making all Medicare enrollment revocations retroactive to the date of non-compliance. Under that framework, form errors and outdated applications are not just administrative delays. They are compliance gaps that can carry financial consequences. The Medicaid-only enrollment path in Section 1A also connects to the nationwide Medicaid revalidation mandate, which requires all states to revalidate their entire Medicaid provider base within 24 months. Providers who need a Medicare enrollment on file to satisfy their state Medicaid program now have a cleaner path to obtain it.

What Happens If You Submit the Old CMS-855B Form?

If a group practice submits the previous version of the CMS-855B after August 2, 2026, the MAC will return the application without processing it. A returned application is not the same as a denial. No enrollment action is taken, no review is performed, and no record of the submission is created in PECOS. The group must start over with the correct form. Under 42 CFR 424.526, one of the enumerated reasons for returning an enrollment application is that the provider submits a paper CMS-855 form that is outdated or has been superseded by a revised version.

The practical cost is time. A returned application adds a minimum of 30 days to the enrollment timeline, and often 45 to 60 days once you account for resubmission, mail transit, and the MAC re-entering the queue. For a group practice that is onboarding a new provider and waiting on the reassignment to process before that provider can bill Medicare, 60 additional days of delay can represent $40,000 to $100,000 in unbilled services, depending on the provider’s specialty and volume.

How to File Reassignments on the Revised CMS-855B

The reassignment workflow on the revised 855B follows a specific sequence. Filing reassignment information incorrectly is one of the top reasons enrollment applications stall, even when the rest of the form is complete.

1. Confirm both the group (via CMS-855B) and the individual practitioner (via CMS-855I) are enrolled or enrolling concurrently in Medicare. The reassignment cannot take effect until both enrollments are active.
2. In Section 1A of the 855B, select the appropriate submittal reason. If this is an initial enrollment that includes a reassignment, select the initial enrollment reason. If the group is already enrolled and adding a new practitioner, select the change of information reason.
3. Complete Section 4H with the individual practitioner’s identifying information: name, NPI, SSN or ITIN, date of birth, and the practice location where they will render services.
4. Have the individual practitioner sign Section 15E. This signature authorizes the reassignment. If the practitioner is not available to sign the 855B, the reassignment can alternatively be reported on their CMS-855I instead.
5. For each additional practitioner reassigning benefits to the group, duplicate Sections 4H and 15E with that practitioner’s information and signature.
6. Include the authorized or delegated official signature for the group in Section 15C as required for any 855B submission.

One critical exception: do not include reassignment information when submitting a revalidation on the CMS-855B unless you are adding new reassignment data, changing existing reassignment details, or terminating a reassignment. Including unchanged reassignment data on a revalidation submission creates unnecessary processing work and can trigger development requests from the MAC.

Paper Filing vs. PECOS Submission

The form revision primarily affects paper filers. Groups that submit through PECOS are already working with the updated field structure, since CMS updates the electronic system to match form revisions. PECOS submissions also process approximately 15 days faster than paper applications on average, according to CMS processing data.

Filing Method	Average Processing Time	Form Version Risk	Reassignment Capability
PECOS (electronic)	15 to 45 days	None (auto-updated)	Reassignment handled inside the system
Paper CMS-855B (revised)	30 to 90 days	Must verify revision date before mailing	New Section 4H and 15E available
Paper CMS-855B (old version)	Returned without processing	Automatic return after August 2, 2026	Not available

For groups that have been filing on paper by preference or by habit, this form revision is a practical reason to transition to PECOS. The electronic system eliminates the version risk entirely and provides real-time application tracking that paper submissions do not offer. That said, we see legitimate reasons practices continue to file on paper, including rural connectivity issues, authorization constraints at multi-site organizations, and legacy workflows at practices that process a low volume of enrollment transactions. For those groups, downloading the current 855B from the CMS enrollment applications page and verifying the revision date before printing is the essential step.

Frequently Asked Questions

Next Steps

Verify your form version before your next 855B submission. If your group is preparing an initial enrollment, revalidation, or change of information, confirm you are using the April 2026 revision. For a complete walkthrough of the CMS-855 form family and which form applies to your situation, see our CMS-855 application guide. If you need to file a reassignment, our guide to the CMS-855R and reassignment process covers the current workflow.