M4S

BCBS Prefix M4S

Blue Cross and Blue Shield of Illinois

Illinois • High-Deductible Health Plan (HDHP), Medicare Advantage, EPO

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 M4S

HDHP

This is a High-Deductible Health Plan (HDHP) prefix. These plans have minimum deductible thresholds set by the IRS. Members often use HSA funds to cover out-of-pocket costs. The plan's claims processing and payer ID are the same as the standard plan, but expect higher patient responsibility amounts on remittance.

Medicare Advantage

This prefix is associated with Medicare Advantage. MA plans combine hospital (Part A) and medical (Part B) coverage, and many include prescription drug coverage (Part D). When billing, confirm whether the plan uses the same payer ID for MA claims as for commercial claims, as many BCBS companies use separate IDs.

EPO

This prefix is associated with an EPO plan. Exclusive Provider Organization coverage combines elements of HMO and PPO plans: members must stay in-network like an HMO, but can self-refer to specialists like a PPO. Out-of-network services are not covered except for emergencies.

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.