What Is PECOS? How Medicare’s Provider Enrollment System Works and Why It Matters

January 31, 2026 / Alex J. Lau / CMS, Medicare, Medicare Enrollment, PECOS

PECOS, the Provider Enrollment, Chain, and Ownership System, is the CMS web-based portal through which healthcare providers and suppliers enroll in Medicare, update their enrollment information, and manage their participation status. Any provider who wants to bill Medicare for services must have an active, accurate PECOS enrollment record. Billing Medicare without an active enrollment, or […]

CMS, Medicare, Medicare Enrollment, PECOS

How to Get Credentialed with Medicare: PECOS Enrollment, Required Documents, Timelines

January 7, 2026 / Alex J. Lau / Credentialing, Medicare Credentialing, PECOS

Medical credentialing specialist analyzing highlighted claims data in a spreadsheet at a healthcare office desk

Medicare credentialing, which CMS calls enrollment, happens in PECOS, and the Medicare Administrative Contractor (MAC) for your region decides whether to approve it. Get the application right and you can bill Medicare. Get it wrong and the MAC sends it back with a request for more information that you have 30 days to answer. This […]

Credentialing, Medicare, Medicare Credentialing, PECOS

Getting In-Network with Medicare

October 9, 2025 / Alex J. Lau / Medicare

Being in-network with Medicare comes down to one decision that many providers never realize they are making, which is whether to participate, stay non-participating, or opt out entirely. Enrollment gets you into the program, and this choice decides how Medicare pays you and what you can charge patients. This post covers that choice, how it […]

In-Network Credentialing, In-Network with Medicare, Medicare, Medicare In-Network

Medicare and Medicaid Fraud: A Growing Problem in the Healthcare Industry

February 2, 2023 / Alex J. Lau / Medicaid Fraud, Medicare Fraud

The Medicare and Medicaid programs provide important support to millions of Americans, offering access to healthcare services for those who may not otherwise be able to afford it. Unfortunately, these programs are also vulnerable to fraud, with criminals exploiting the system to enrich themselves at the expense of taxpayers and patients. Medicare fraud and Medicaid […]

Medicaid, Medicare, Phantom billing, Upcoding, Whistleblower Protection Act

How MACRA Changed Medicare Reimbursement, and What It Still Means for Your Practice

August 23, 2017 / Alex J. Lau / MACRA

MACRA changed Medicare reimbursement by ending a model that used to be fairly simple, where you saw the patient, billed Medicare, and got paid based on volume. That model started to shift back in 2015, when Congress passed the Medicare Access and CHIP Reauthorization Act, better known as MACRA. The law rebuilt the way Medicare […]

Advanced APM, CMS, Medicare, MIPS, QPP, Value-Based Models