G8S

BCBS Prefix G8S

Blue Cross and Blue Shield of Illinois

Illinois • POS, EPO, Medicare Advantage

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 G8S

POS

POS coverage under this prefix operates on a tiered system. Tier 1 (in-network with referral) provides the highest coverage. Tier 2 (in-network without referral) provides moderate coverage. Tier 3 (out-of-network) provides the lowest coverage. Verify which tier applies before submitting the claim.

EPO

This is an Exclusive Provider Organization (EPO) prefix. EPO plans do not cover out-of-network care except in genuine emergencies. Members can see any in-network specialist without a referral from their primary care physician. Claims for out-of-network non-emergency services will be denied.

Medicare Advantage

This prefix includes Medicare Advantage coverage. MA plans follow CMS guidelines for timely filing (365 days from date of service), which may differ from the commercial plan's deadline. The payer ID for Medicare Advantage claims may differ from the standard commercial payer ID. Verify before submitting.

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.