Medicare Advantage (MA) & Traditional Medicare

  • Sequestration deduction (commonly 2%) often appears on EOBs as adjustment code 253.
  • MA can be administered by private carriers (Humana, UHC, Aetna, BCBS, etc.).

ID & Card Heuristics (quick cues)

  • BCBS Commercial often shows prefix + digits; BCBS Medicare Advantage commonly mixes letters+digits similar to Medicare IDs.
  • Aetna Commercial IDs frequently start with W; Aetna MA often 12 digits starting with 10 (older cards used ME prefix).
  • Humana Commercial: digits; Humana MA: 8 digits starting with H.

Pharmacy (Part D) & Medicaid indicators

  • Part D PCNs often include tokens like ADV, MEDD, PARTD, MEDDAET, etc.
  • Medicaid PCNs frequently contain MCAID (e.g., RXMCAID, MCAIDOH).

Routing tips

  • If the EOB shows code 253 and MA branding, route claim logic through MA plan rules, not straight CMS MAC.
  • Use BIN/PCN + ID heuristics + age to disambiguate MA vs commercial and pick the right payer tree.

Next

We can expand this with your internal rulebook (per payer, per state) and live search of our BIN/PCN registry.