A GP referral is required by Medicare to ensure that patients are seeing the correct provider for their particular condition. This way you are entitled to a Medicare rebate. Most GP referrals will last for 12 months unless otherwise specified on the referral by the GP. Specialist referrals only last for three months.However, if you do not wish to provide a GP referral, you can still see Dr Kliman but you will not be able to claim a refund from Medicare..