Prior authorization means that your doctor must get approval from Blue Shield before administering specific medications or performing a particular medical service or operation. Without this prior approval, Blue Shield may not pay for your medication or medical care, and you will have to pay out of pocket.
Go to 2025 Medical and Part B Medication Prior Authorization Page
Medical care
Access the criteria used to make decisions about the medical care you receive.
Part B medications
Part B medications are drugs you get at a doctor's office or in a hospital outpatient setting.
About Part B Step Therapy
If you are enrolled in a Blue Shield Medicare (PPO) plan, your Part B drugs may be subject to step therapy.
View the Part B Step Therapy criteria:
About Part B Medication Authorization
If you are enrolled in Blue Shield Medicare (PPO), Blue Shield 65 Plus (HMO), Blue Shield 65 Plus Choice Plan (HMO), Blue Shield 65 Plus Plan 2 (HMO), Blue Shield Advantage (HMO), Blue Shield AdvantageOptimum Plan (HMO), Blue Shield AdvantageOptimum Plan 1 (HMO), Blue Shield Inspire (HMO), and Blue Shield TotalDual Plan (HMO D-SNP) your Part B drugs may be subject to prior authorization.
If you are enrolled in the Blue Shield Medicare (PPO), your oncology-related Part B drugs may be subject to updated prior authorization requirements, starting January 1, 2026. Access the criteria used to make decisions about your oncology-related medications by clicking the link below.
View the Part B medication criteria
Remember, it’s always important to check that the service or drug you need is a covered benefit under your plan. For any questions about prior authorization, please call Customer Service at the number on your Blue Shield member ID card
Blue Shield of California is an HMO, HMO D-SNP, and a PDP plan with a Medicare contract and a contract with the California State Medicaid Program. Enrollment in Blue Shield of California depends on contract renewal.
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Page last updated: 11/18/2025