As payer audits become more frequent and complex, laboratories and healthcare providers must be equipped to respond effectively. While laboratories can rely on the ordering provider’s determination of medical necessity, laboratories still play a role in ensuring medical necessity. Laboratories may want to verify that all claims include clear medical necessity documentation. Laboratories should routinely review and stay up to date on payor policies, which can change frequently and vary between Medicare, Medicaid, and private insurers. When an audit occurs, laboratories should prepare all requested documentation carefully and include any supplemental materials that support the claim.