Effective November 2, 2025, Medicare’s update to LCD L36351, which governs the use of special stains and immunohistochemistry (IHC) in pathology, represents a meaningful shift in how pathology labs document, justify, and code diagnostic testing. For health systems, this change heightens reimbursement risk if diagnostic detail and coding accuracy aren’t tightly aligned.
The update reinforces the need for medical necessity and precise documentation - central to maintaining compliance, reimbursement accuracy, and quality care. For pathology departments and medical coding teams, this is an opportunity to elevate documentation standards to align with CMS expectations and strengthen coding quality across the board.
CodaMetrix is working with leading health systems to prepare for these changes - helping teams identify documentation gaps early, enhance coding accuracy, and ensure pathology reporting meets Medicare’s new requirements.
Many pathology departments rely on reflex panels or standing orders to streamline workflows. Under LCD L36351, stains must now be ordered with clear, case-specific rationale, and that reasoning must be documented within the pathology report. While most cases will require an H&E review before ordering special stains or IHC, LCD L36351 allows for limited exceptions when medically necessary based on established diagnostic protocols.
Labs that fail to include sufficient justification in reports could see more denials, while those that proactively strengthen documentation will better protect reimbursement and patient care.
Lab Reports must clearly specify:
LCD L36351 provides explicit expectations for several high-volume disease areas:
These updates reinforce that test selection should reflect diagnostic findings and medical necessity, not routine ordering, thus ensuring each test is supported by clear documentation within the pathology report.
LCD L36351 is a reminder that high-quality coding begins with high-quality documentation. When the clinical rationale is clear, coding accuracy and timely reimbursement follow.
At the same time, these expectations can add workload to already stretched teams. Partnering with technology that reduces manual coding tasks or flags potential documentation gaps can help pathologists and coding teams focus on what matters most: accurate interpretation and clinically meaningful reporting.
When documentation and medical coding operate in sync, compliance becomes a byproduct of quality, not an added burden.
As the LCD L36351 revisions take effect on November 2, 2025, proactive preparation will help health systems safeguard reimbursement and maintain compliance without sacrificing efficiency. Strengthening documentation and coding alignment today sets the foundation for more accurate, efficient, and patient-focused pathology practices. CodaMetrix customers are already taking steps in this direction, our teams are partnering closely with pathology and coding departments to identify documentation gaps early, enhance coding quality, and ensure readiness well ahead of these policy changes.
