For many of our health plans, the patient is required to coordinate all care through their primary care physician. If the patient's primary care doctor determines their patient needs to seek treatment from a specialist, a referral must be obtained. If a referral is not obtained, the insurance claim will either pay at a reduced, out-of-network rate, or not at all.
If, upon enrollment into a new plan, you are required to select a primary care physician, this is a good indicator that referrals will be required to see a specialist. Your human resources department should advise you of this referral requirement during your open enrollment period.
Most insurance cards indicate these requirements on the back of the card or by listing a primary care physician (PCP) on the front of the card.