A3N

BCBS Prefix A3N

Blue Cross and Blue Shield of Illinois

Illinois • Medicare Advantage, HMO, Traditional Indemnity

Billing essentials

Provider phone
(877) 860-2837
Electronic payer ID
00621
Claims mailing address
P.O. Box 650712 Dallas, TX 75265-0712
Timely filing limit
180 daysCompare all plans
Prior authorization phone
(800) 654-7385

Coverage under prefix A3N

Medicare Advantage

Under this prefix, the member may have Medicare Advantage coverage administered by this BCBS plan. MA claims are subject to CMS regulations in addition to the plan's own policies. Balance billing restrictions apply. Verify the member's specific MA plan details and confirm the correct payer ID for electronic submission.

HMO

HMO coverage means this member must use providers within the plan's network. A primary care physician serves as the care coordinator and must authorize specialist referrals. Emergency services are the primary exception to the network requirement. Always verify referral status before providing non-emergency specialty care.

Traditional Indemnity

Under this indemnity prefix, the member has fee-for-service coverage. There is no provider network, no referral requirement, and no primary care physician gatekeeper. Claims are processed based on the plan's fee schedule. While less common than managed care plans, indemnity coverage is still offered by some BCBS companies.

About Blue Cross and Blue Shield of Illinois

State's only statewide customer-owned health insurer and independent licensee of the Blue Cross Blue Shield Association. Serves Illinois with commercial, Medicare, Medicaid and other plans.