Generally speaking, if you have a “PPO” type health insurance, you do not need a referral. Most “HMO” patients do require a referral. Examples of HMO’s in Phoenix include HealthNet, Aetna, and others. BCBS HMO, however does not require a referral, while Mercy Care Advantage does. All patients with insurance that requires a referral will need to obtain authorization prior to scheduling an appointment.