CERT stands for Comprehensive Error Rate Testing and is done by the MACs to determine the percentage of improper payments paid out by Medicare and their causes causes/areas.
The results of the CERT reports can be seen at the CMS CERT Report website and the Health and Human Services Agency Financial Reports website.
If a provider/entity's documentation is requested to support a claim but is not provided in 45 days, the claim is presumed to be in error and the payment can be fully or partially revoked. These can be submitted electronically or via post ( requestee pays the postage). No release of information needs be signed by the patient as was part of the paperwork they signed when enrolled.
There is a 5 level Appeal Process for denied clams (this often shows up on exams).
Level One: Redetermination - Must be requested within 120 days of the denial date. Requires the submission of supporting documents and filing out a CMS-20027 form.
Level Two: Reconsideration - Done by a Qualified Independent Contractor (QIC) within 180 days of the level one appeal or within 60 days to pause the MAC's recoupment.
Level Three: Administrative Law Judge Review - If reconsideration is also denied, and is at least $180.00, the provider can appeal the case to an administrative law judge within 60 days.
Level Four: Medicare Appeals Council Review - Also have to initiate within 60 days.
Level Five: Federal District Court Review - the final review. Must be at least $1,900 in dispute (as of 2025). Must again make appeal within 60 days.
Additional information, unlikely to be on any exam, but my inner MBA went down a rabbit hole:
It is actually conducted by two CMS MAC contractors who audit 37,500 (as of 2025) randomly chosen Physician Fee-For-Services (FFS) claims submitted to Medicare MACs and DMACs. These contractors are:
CERT Review Contractor: Empower AI, Inc. (previously NCI Information Systems, Inc.). This company has multiple federal contracts in many areas. It is majority owned by private equity group KKR (Kohlberg Kravis Roberts & Co.) which in turn is majority owned by BlackRock Fund Advisors
CERT Statistical Contractor: The Lewin Group, Inc. is owned by IngenX which is owned by United Health Group. Are a section of UHG's OptiServe which is partnership of UHG and Optium. It does various federal health services. Interestingly, it's parent owns about 15% of the US insurance market. It's largest shareholders are The Vanguard Group and Blackrock.