If a code should not be reported with modifier 50 per CPT guidance (CPT indicates to bill the procedure X2 and not add the modifier), BUT the Medicare Advantage insurer has a Modifier 50 policy that allows the provider to bill a bilateral code with modifier 50 or RT/LT (the policy does not make any reference to CPT guidelines) as long as the MPFS RVF is not other than 1.....is that appropriate and allowable per Medicare guidelines? Is it correct to bill according to the Medicare Advantage policy even if that policy differs from the CPT guidance? Really looking forward to your assistance and feedback. Thank you!