Program Integrity

The Lewin Group works with the federal government, state agencies, and private health plans to facilitate timely, accurate, and appropriate reimbursement.

The Lewin Group brings together dedicated policy experts — renowned for their intellectual energy, analytical talent, integrity, and commitment to client satisfaction–with experienced reimbursement consultants to detect and mitigate improper payments for the federal government, state agencies, and private health plans.

We facilitate accurate payment for medically necessary and covered services delivered efficiently to eligible beneficiaries. Our work includes fraud and abuse detection and supports timely modifications to payment systems, policies, and methods to reduce payment error.


We work with our clients to provide comprehensive analysis, help them overcome obstacles, and implement effective strategies to facilitate payment integrity.

Payment Accuracy Assessment
  • Assess payment accuracy using a variety of quantitative, statistical methods
  • Identify system vulnerability
  • Validate coding, medical necessity, and reimbursement
Fraud and Abuse Detection
  • Develop pre- and postpayment screening models
  • Identify outliers
  • Develop provider network management strategies
Mitigation Strategies, Including Provider Education
  • Design, implement, and evaluate education programs
  • Benchmark performance
  • Establish medical necessity

 See the full list of Lewin services
 See all Program Integrity publications


CMS Program Integrity

Payment error rate measurement (PERM) and comprehensive error rate testing (CERT)

In the mid-1990s, we helped CMS develop the concept of statistically sampling and then reviewing sampled paid claims for errors to estimate the rate of improper payments in Medicare. We then extended the methods to Medicaid. CMS uses the programs to satisfy the requirements of the Improper Payments Elimination and Recovery Act (IPERA). Today, we are the statistical contractor for both CERT (Medicare) and PERM (Medicaid) and have been engaged in both programs since their inception.

These programs are highly visible across the executive branch and Congress. CMS uses them to monitor progress in reducing payment error rates.

  • The results of CERT and PERM achieve high visibility across the executive branch and Congress, and they are used to help guide CMS, Medicare Authorized Contractors and the states’ error rate reduction efforts.
  • These reports help fulfill the goals of the Improper Payments Elimination and Recovery Act (IPERA).
  • CMS and the states act to reduce errors based on the findings of CERT and PERM.
  • Changes in the CERT and PERM error rates over time is a primary measure of the progress made in reducing improper payments.

"Throughout the engagement, Lewin consultants listened to us and delivered superb analyses and thoughtful guidance–not canned solutions.