IMMEDIATE (effective 2026-04-21): Billing team must update authorization and claim processing rules in billing software: (1) CPT 82731 (fetal fibronectin) is COVERED ONLY when ALL criteria are met—intact membranes, cervical dilation <3cm, gestational age 24+0 to 34+6 weeks, and results available for real-time clinical decision-making. Implement system edits to reject claims outside this window. (2) Repeat testing (CPT 82731) requires patient to remain symptomatic 2+ weeks after prior negative result—update prior authorization logic to enforce this rule. (3) HCPCS S3652 (salivary hormone test) and 40+ biomarker tests (CPT codes 0247U, 81291, 82085, 82103, 82131, 82542, 82677, 82728, 83006, 83516, 83518, 83519, 83520, 84112, 84144, 84145, 84210, 84466, 84550, 85415, 86140, 86141, 88324, 84560 and others) are NON-COVERED as experimental—update denial rules in billing system and flag claims for automatic rejection. (4) Do NOT cover CPT 82731 following cervical cerclage (CPT 59320). (5) Do NOT cover ultrasound CPT 76815 for amniotic fluid sludge evaluation. (6) Update encounter templates and clinical decision support to remind OB/GYN providers of these restrictions at point of care. Provider education required to prevent ordering of non-covered biomarkers. Claims submitted without meeting medical necessity criteria will be denied; failure to implement these rules will result in claim rejections and compliance issues.