Medicare AdvantageAdministrativeMedium impact
MAPAP103 - Member Identification - Removed Prefix that are no longer active including XMX, XMI, XML, ZLT, and X2B. Updated ID Cards examples.
Blue Cross of Idaho·ID·Medical Policy
Effective date
Apr 1, 2026
We identified it
Jun 19, 2026
Summary
Blue Cross of Idaho removed five inactive Medicare Advantage member ID prefixes (XMX, XMI, XML, ZLT, and X2B) from their system and updated ID card examples. Only XMM (True Blue HMO) and XMA (Secure Blue PPO) prefixes remain active for Medicare Advantage members.
Action Required
Immediately: Billing team must update member identification procedures to only recognize XMM (True Blue HMO) and XMA (Secure Blue PPO) as valid Medicare Advantage prefixes. Remove XMX, XMI, XML, ZLT, and X2B from any system validation rules or reference materials. Train front desk staff to verify eligibility online or by phone if encountering old prefix formats on member cards.