PECOS Medicare Enrollment: Complete Guide

TL;DR — PECOS is CMS’s online system for Medicare enrollment: initial applications, enrollment changes, reassignments, revalidation, and status tracking. You need a CMS I&A account before you can log in. A few forms stay paper-only — CMS-588 EFT, CMS-460 participation, CMS-855S (DMEPOS via the NSC), and opt-out affidavits. PECOS — the Provider Enrollment, Chain and Ownership System — is CMS’s online platform for Medicare enrollment. If you need to enroll as a Medicare provider, update your enrollment information, or revalidate your existing enrollment, PECOS is where most of that happens.

PECOS replaced the default paper-filing process for most provider types. It’s faster than paper, provides real-time status tracking, and is the preferred pathway for most Medicare Administrative Contractors.

What PECOS does

PECOS is used for:

• Initial enrollment — submitting new enrollment applications (equivalent to CMS-855I, CMS-855B)
• Enrollment changes — updating practice location, correspondence address, specialty, or other information in your existing enrollment
• Reassignments — linking individual providers to group practices via CMS-855R
• Revalidation — confirming that your existing enrollment is current every 5 years (3 years for high-risk providers)
• Application status tracking — checking where your application is in the review process

PECOS is not used for:

• CMS-588 (EFT Authorization) — paper only
• CMS-460 (Participating Agreement) — paper only
• CMS-855S (DMEPOS supplier enrollment) — handled by National Supplier Clearinghouse (NSC), not PECOS
• Opt-out affidavits — paper, filed with MAC

How PECOS is organized

PECOS has two access layers:

I&A (Identity & Access Management)

Before you can use PECOS, you need a CMS I&A account — a separate login system that manages identity verification and access to CMS systems. Think of I&A as the authentication layer; PECOS is the application layer.

Your I&A account must be:

• Linked to your NPI (for individual providers)
• Or linked to an organization’s NPI (for authorized officials accessing organization enrollments)

Creating an I&A account and linking to PECOS →

PECOS enrollment records

Once in PECOS, each enrolled provider or organization has an enrollment record. From this record, you can:

• View your current enrollment status
• Initiate updates and changes
• Check revalidation due dates
• Manage reassignments

PECOS for individuals vs. organizations

Individual providers access PECOS with their own I&A credentials tied to their individual NPI. Their enrollment record contains their CMS-855I information.

Organizations access PECOS through an authorized official or delegated official linked to the organization’s NPI. The authorized official manages the organization’s CMS-855B enrollment and can also see individual provider reassignments to that organization.

Delegated officials are individuals an authorized official designates to have access to PECOS on behalf of the organization. A practice manager or billing lead can be a delegated official without being the legal authorized official.

PECOS timeline: how long does it take?

PECOS doesn’t provide instant enrollment — it’s the submission mechanism, not the approval mechanism. After you submit in PECOS, your application enters the MAC review queue.

Times vary by MAC jurisdiction and current workload. PECOS status updates reflect movement through the review queue.

What PECOS status codes mean

Once your application is submitted, PECOS shows one of several status indicators:

Check status at least every 30 days after submission. If your application is “Pending Completion,” the MAC has sent you a development letter asking for more information — respond within 30 days or the application is denied.

The development process

During review, your MAC may contact you to request additional information or clarification — this is called “development.” Common development requests:

• Missing or expired license information
• Ownership disclosure questions
• Discrepancy between application and NPPES data
• Additional documentation for specialty enrollment
• Adverse history clarification

Development requests are sent to your correspondence address. ⚠️ If your correspondence address is outdated, you’ll miss development letters, miss the 30-day response window, and your application will be denied.

PECOS for multiple providers

Practices with multiple enrolled providers can access all their enrollments through the appropriate PECOS accounts:

• Each individual provider has their own I&A credentials
• The organization’s authorized official (or delegated official) can see all providers reassigned to the organization
• Billing companies can be granted delegated access by the authorized official

When PECOS doesn’t work

Known issues with PECOS:

• NPPES sync delay — NPI changes in NPPES take 24–72 hours to reflect in PECOS. Don’t file a PECOS application immediately after updating NPPES.
• Session timeouts — PECOS times out after inactivity. Save your application frequently.
• Browser compatibility — PECOS works best in Chrome or Edge; older browsers may have issues.
• I&A identity verification — New I&A accounts require identity verification that can take 1–3 business days.
• Organization access issues — If an authorized official has left the organization and access was tied to their I&A account, getting new access requires contacting the MAC and providing documentation.

PECOS troubleshooting guide →

Getting started in PECOS

1. Create your I&A account and link to PECOS
2. Submit your enrollment application
3. Track status — check in every 30 days
4. Respond to any development requests promptly
5. Receive PTAN and enrollment approval letter
6. File CMS-588 (paper) for EFT

Related pages

• How to Create a PECOS Account
• Submitting Your Medicare Enrollment in PECOS
• PECOS Revalidation Guide
• PECOS Troubleshooting
• CMS-855I vs. PECOS: Which to Use

Questions about PECOS? Mae can walk you through any step. Ask Mae → Free Metolius Health enrollment audit →