There are medicines on the Pharmaceutical Benefits Scheme (PBS) that require medical practitioners to obtain authority from the Department of Human Services to prescribe them. Some of the examples are for cancer treatment, palliative care and pain management, etc. 

The most frequently used method is the Authority Free-call service, where an administrative officer decides if the medical practitioner can have the necessary authority.  

There are various types of Authority Scripts and reasons for authority prescriptions, including:

• A quantity or repeat is prescribed which is larger than the usual PBS quantity
• The medication requires additional monitoring, tests or expertise at the of prescribing
• The medication is a high cost drug
• The medication has an equivalent but equally effective option which cannot be used for some reason

Authority required benefits - Authority required benefits fall into two categories:

• Authority required benefits are restricted benefits that require prior approval from the Department of Human Services or the DVA (noted as Authority required)
• Authority required (STREAMLINED) benefits are restricted benefits that do not require prior approval from the Department of Human Services or the DVA but require the recording of a streamlined authority code (noted as Authority required (STREAMLINED)).

You can read more about authority prescriptions here.