> ## Documentation Index
> Fetch the complete documentation index at: https://www.practiceownersguide.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Medicare enrollment via PECOS

> Enroll the practice and its providers in Medicare: I&A account, the 855 applications, EFT via CMS-588, and revalidation.

Medicare enrollment runs through PECOS, CMS's online system. It is its own
world: separate from CAQH, separate from commercial payers, with its own forms
and its own clock (typically 45-90 days).

```mermaid theme={null}
%%{init: {'themeVariables':{'fontFamily':'inherit','fontSize':'14px'}}}%%
flowchart TB
    subgraph top [" "]
        direction LR
        A[I&A account] --> B[PECOS application] --> C[855B practice + 855I providers]
    end
    subgraph bottom [" "]
        direction LR
        D[CMS-588 EFT section] --> E[MAC review] --> F[Approval + effective date]
    end
    C --> D
    style top fill:none,stroke:none
    style bottom fill:none,stroke:none
```

## Create the I\&A account

Everything starts at the CMS Identity & Access Management System. Each person
uses their own login (sharing credentials violates CMS rules). The practice's
authorized official creates the account, then can delegate staff.

## File the right 855s

| Form | Who it enrolls                                                     |
| ---- | ------------------------------------------------------------------ |
| 855B | The practice entity (clinics, group practices)                     |
| 855I | Each individual physician or practitioner                          |
| 855R | Reassignment: lets the practice bill for the individual's services |
| 855S | DMEPOS suppliers only                                              |

A typical new practice files one 855B, one 855I per provider, and an 855R
linking each provider to the group. File them together in PECOS.

## Set up EFT with the CMS-588

The EFT section of the PECOS application is the CMS-588. You need the exact
entity name, the bank routing and account numbers, and a voided check or bank
letter upload. The deposit account must belong to the enrolled entity.
Changing banks later means a new CMS-588 through PECOS or your MAC
(see the Medicare pages in the [payer directory](/reference/payers)).

## Know your MAC

CMS outsources processing to regional Medicare Administrative Contractors
(Novitas, Palmetto, Noridian, and others, by state). The MAC is who you call
about a stuck application and where paper CMS-588s go. Find yours on
cms.gov, then use the matching portal page:
[Novitas](/reference/payers/medicare-novitas),
[Palmetto](/reference/payers/medicare-palmetto).

## After approval

Note your PTAN and your effective date. Medicare allows limited retroactive
billing (generally 30 days before the application receipt date), so date of
first Medicare patient matters. Then calendar **revalidation**: Medicare
requires it roughly every 5 years and deactivates billing if you miss it.

<Note>
  Not planning to bill Medicare at all? You still must choose a position:
  non-participating, or formally opted out with private contracts. See the
  [cash-pay model](/concepts/practice-models-cash-pay).
</Note>

## Related

* [Get credentialed](/guides/get-credentialed)
* [Medicaid enrollment](/guides/medicaid-enrollment)
* [Enroll in EFT and ERA](/guides/enroll-eft-era)
* [Payer EFT/ERA enrollment directory](/reference/payer-enrollment-directory)