K5M

BCBS Prefix K5M

Blue Cross and Blue Shield of Illinois

Illinois • High-Deductible Health Plan (HDHP), PPO, 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 K5M

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.

PPO

PPO coverage under this prefix means the member can access any provider. In-network providers have negotiated rates with the plan, while out-of-network providers are reimbursed based on usual and customary charges. Prior authorization is generally not required for routine services but may be needed for high-cost procedures.

Medicare Advantage

Medicare Advantage coverage under this prefix means the plan administers Medicare Part A and Part B benefits on behalf of CMS. These claims may have different processing rules than commercial claims, including different prior authorization requirements and appeal timelines. CMS timely filing rules (365 days) typically apply.

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.