US lawFederal (United States)Agency guidanceCMS Medicare Internet-Only ManualsPub. 100-04Chapter 56Medicare Claims Processing Manual (Pub. 100-04), Ch. 5 § 6FillerLength: 13 wordsOfficial source 6 – Filler 24-30 X(07) 7 -- A/B MAC (B) Number 31-35 X(05)PreviousMedicare Claims Processing Manual (Pub. 100-04), Ch. 5 § 5NextMedicare Claims Processing Manual (Pub. 100-04), Ch. 5 § 8