All PlansCoverageMedium impact
Germline Genetic Testing for Hereditary Diffuse Gastric Cancer (CDH1, CTNNA1)
Blue Cross & Blue Shield of Mississippi·Oncology, Gastroenterology, Family Medicine +2 more·Medical Policy
We identified it
Jun 20, 2026
Summary
New medical policy establishes coverage criteria for germline genetic testing for hereditary diffuse gastric cancer (CDH1 gene variants). CDH1 testing is considered medically necessary for specific high-risk patients including those with diffuse gastric cancer before age 50, bilateral lobular breast cancer before age 70, or qualifying family history. CTNNA1 testing remains investigational and not covered.
Action Required
Immediately: Billing team must review genetic testing orders for CDH1 variants to ensure patients meet the specific medical necessity criteria outlined in policy A.2.04.154 before submitting claims. Verify documentation includes qualifying diagnoses (diffuse gastric cancer before age 50, bilateral lobular breast cancer before age 70, or specified family history patterns). Do not bill for CTNNA1 testing as it is considered investigational. Update pre-authorization workflows to check these criteria.