S4M

BCBS Prefix S4M

Blue Cross and Blue Shield of Illinois

Illinois • HMO, HDHP, 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 S4M

HMO

This prefix is linked to an HMO plan. Health Maintenance Organization coverage requires members to use in-network providers and coordinate care through a designated primary care physician. Referrals are typically required for specialist visits. Claims submitted without proper referral documentation may be denied.

HDHP

Under this HDHP prefix, the member's plan has a higher deductible than traditional coverage. This affects patient cost-sharing but does not change how claims are submitted or processed. Use the same payer ID, claims address, and filing procedures listed above. Verify the member's remaining deductible before estimating patient responsibility.

Medicare Advantage

Medicare Advantage (MA) coverage means this member receives their Medicare benefits through a private BCBS plan rather than through original Medicare. MA plans may have different payer IDs and claims addresses than the commercial plan. Check with the payer to confirm the correct submission details for Medicare Advantage claims.

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.