You can fax your preauthorization, along with supporting documentation, to 1-866-311-9603. We accept faxes between 8 a.m. and 4:30 p.m. Monday through Friday.

Or, you can mail it to:

Blue Cross Blue Shield of Michigan
P.O. Box 2227
Detroit, MI 48231-2227
Attention: Preauthorization, Provider Inquiry
Service Mail Code: 0450

We respond to nonurgent preauthorizations 15 days after receiving them.

For an urgent request, you must attest with a signature that the patient's condition is unstable and a delay more than 72 hours could jeopardize their life or limb, or subject them to adverse health consequences if they don't get the requested care.

We respond to urgent requests within 72 hours.