BCBSRI follows CMS payment policies with respect to bilateral services. In limited cases, CMS and CPT coding guidelines may differ in the correct use of modifier 50. In those cases, BCBSRI will follow the CPT coding guidelines. For example, some CPT codes have “unilateral or bilateral" in the descriptor, making it clear the service is inherently bilateral. While CMS may allow use of a bilateral modifier, BCBSRI will follow CPT guidelines and deny the claim if filed with a bilateral modifier.