Section 411.25 - Primary payer's notice of primary payment responsibility(a) If it is demonstrated to a primary payer that CMS has made a Medicare primary payment for services for which the primary payer has made or should have made primary payment, it must provide notice about primary payment responsibility and information about the underlying MSP situation to the entity or entities designated by CMS to receive and process that information.(b) The notice must describe the specific situation and the circumstances (including the particular type of insurance coverage as specified in § 411.20(a) ) and, if appropriate, the time period during which the insurer is primary to Medicare.(c) The primary payer must provide additional information to the designated entity or entities as the designated entity or entities may require this information to update CMS' system of records.54 FR 41734, Oct. 11, 1989, as amended at 55 FR 1820, Jan. 19, 1990; 73 FR 9684 , Feb. 22, 2008