The short answer: When your Medicare enrollment details change, you report a change of information. Physicians and non-physician practitioners can do that online in PECOS or on the paper Medicare enrollment application (Form CMS-855I). PECOS is CMS's system for reviewing and updating your information and reporting changes to your enrollment record.
What counts as a change of information
The federal rule names the main reportable events for physician and non-physician practitioner practices: a change of ownership, an adverse legal action, and a change, addition or deletion of a practice location. Every other change in enrollment must be reported too, on a longer window.
Not every field counts. CMS's CMS-855I says fields marked optional don't need to be reported as a change of information, though CMS recommends keeping them up to date if you reported them.
Where to report: PECOS or the paper form
You can make a change to your enrollment information through PECOS or with the paper CMS-855I. Your Medicare contractor handles enrollment applications and can answer questions about yours. See CMS's PECOS page.
CMS says the CMS-855R has been discontinued and reassignment actions are now reported on the CMS-855I.
Reporting windows in the regulation
Under 42 CFR 424.516(d), physicians, non-physician practitioners, and their organizations must report a change of ownership, an adverse legal action, or a change in practice location to their Medicare contractor within 30 days. All other changes in enrollment must be reported within 90 days. (eCFR, 42 CFR 424.516)
Other provider and supplier types have similar 30- and 90-day rules under 42 CFR 424.516(e).
Behind these rules, CMS maintains an active enrollment status when you certify that you meet, and continue to meet, its requirements, and CMS verifies that you meet them.
The regulation also says why reporting matters: under 42 CFR 424.535(a)(9), CMS may revoke a currently enrolled provider or supplier's Medicare enrollment when the provider or supplier did not comply with the reporting requirements in 42 CFR 424.516(d) or (e). (eCFR, 42 CFR 424.535)
Changing, adding or removing a practice location
On the CMS-855I, if you're changing a practice location already on file, or adding or removing one, you check the matching box, give the effective date and complete the fields in that section.
For a move, one Medicare contractor, First Coast Service Options (FCSO), says it is best practice in PECOS to end-date the old information and add the new information when the information is entirely new. Your Medicare contractor's instructions may differ.
Two instructions on the group form, CMS-855B (revision 12/2025), apply here:
- For a new practice location, CMS-855B says the date you give should be the date you saw your first Medicare patient at that location.
- The practice location must be the physical place where you see Medicare patients. It can't be a P.O. Box.
For groups, CMS-855B says sections 1, 2A1, 3 and 15 must always be completed when you report any change, along with the section that is changing. If your group is working through location or reassignment updates, see our group practices page.
NPPES is a separate update
CMS says updates to your NPI record in NPPES do not automatically update your Medicare enrollment information. So a new address in NPPES doesn't carry over to your Medicare enrollment record on its own. CMS's CMS-855I says your name, Social Security number, legal business name, taxpayer identification number, and NPI must match exactly in PECOS and NPPES. For how the two systems differ, see PECOS vs NPPES.
Revalidation is separate from a change of information. For that, see our recredentialing and revalidation service.
Not sure your Medicare enrollment matches your current practice details?
A credentialing audit is a preliminary review of where your credentialing stands. You receive a written report of the current issues we find with your credentialing.
Approval, effective dates, and processing timelines are outside our control.
See our Medicare PECOS support.
Sources
- CMS, Manage Your Enrollment (page last modified 03/04/2026)
- eCFR, 42 CFR 424.516(a), (d), (e) (point-in-time 2026-10-15)
- CMS, Form CMS-855I (revision 05/23)
- CMS, Form CMS-855B (revision 12/2025)
- CMS, NPI Fact Sheet (December 2024)
- CMS, PECOS hub page (07/31/2026)
- First Coast Service Options (FCSO), Provider enrollment effective dates (page date July 2, 2026)
- eCFR, 42 CFR 424.535(a)(9) (point-in-time 2026-10-15)