A4W

BCBS Prefix A4W

CareFirst BlueCross BlueShield

Maryland/District of Columbia/Northern Virginia • POS, Medicare Advantage, HMO

Billing essentials

Provider phone
(800) 842-5975
Electronic payer ID
580
Claims mailing address
10455 Mill Run Circle, P.O. Box 825, Owings Mills, MD 21117
Timely filing limit
180 daysCompare all plans
Prior authorization phone
(866) 773-2884

Coverage under prefix A4W

POS

This prefix is linked to a POS plan. Point of Service coverage gives members a choice at the time of service: use the HMO-style in-network benefit with a referral for lower costs, or access out-of-network providers at reduced coverage levels. The billing approach depends on which option the member chooses.

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.

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.

About CareFirst BlueCross BlueShield

Independent licensee of the Blue Cross Blue Shield Association serving Maryland, District of Columbia and Northern Virginia.