A referral letter from a GP to a specialist is generally valid for twelve months, counted from the first specialist appointment rather than the letter date. Referrals from one specialist to another last three months. Indefinite referrals exist for ongoing management of chronic conditions.
An expired referral means the specialist visit may not attract a Medicare rebate. Renewing is straightforward: a short GP consultation, in person or by telehealth, can issue a new referral and update the specialist on any changes since the last visit.