GP-Referred MRI Under Medicare: What You Can and Can't Request

Unlike CT and X-ray, where most referred studies attract a Medicare rebate, MRI eligibility in Australia is tightly restricted. Only specific clinical indications listed on the Medicare Benefits Schedule (MBS) can be requested by a GP, and the scan must be performed on a Medicare-eligible machine.

This creates a common and frustrating scenario: a GP writes a clinically sound MRI referral, the patient books, and only at the clinic do they learn the scan will cost several hundred dollars out of pocket because the indication or the machine doesn't qualify.

Understanding the broad categories of GP-eligible MRI - and knowing when to check MBS Online before writing the referral - prevents most of these situations. This guide covers the categories at a general level; item descriptors change periodically, so always verify current criteria at mbsonline.gov.au before relying on them.

GP-referred MRI items for adults cover a limited set of indications, broadly including:

• Head - for unexplained seizure(s), or for unexplained chronic headache where there is a suspicion of intracranial pathology. Note the descriptors contain specific wording; "headache" alone does not qualify. • Cervical spine - for cervical radiculopathy, or for cervical spine trauma. • Knee - following acute knee trauma, with specific criteria around the clinical findings and the timing of the injury.

Each item descriptor contains precise eligibility language. A referral that says "MRI brain - chronic headache" may not meet the descriptor, whereas one that documents the suspicion of intracranial pathology and the clinical basis for it will.

Mirror the descriptor language where it genuinely applies to your patient - never retro-fit an indication to gain a rebate, but do describe the clinical picture in terms the descriptor recognises.

Medicare provides a wider range of GP-referrable MRI items for patients under 16 years of age, reflecting the priority of avoiding ionising radiation in children.

The under-16 categories broadly include MRI of the head (for indications such as unexplained seizures, unexplained headache with suspected pathology, and some developmental concerns), the spine, the knee, the hip, and the wrist for suspected scaphoid fracture, among others.

Because the paediatric list is broader than the adult list, GPs sometimes assume an indication that qualifies in a child also qualifies in an adult - it frequently does not. Check the current under-16 item descriptors on MBS Online, and note the patient's age and date of birth clearly on the referral so the clinic can bill the correct item.

For guidance on preparing children for MRI, see our paediatric imaging referrals guide.

Not every MRI machine in Australia can bill Medicare, and among those that can, licensing differs:

• Fully licensed (fully eligible) machines can perform any MBS-listed MRI service with an appropriate referral. • Partially licensed machines can only bill Medicare for a subset of items - typically the GP-referrable items. • Unlicensed machines cannot bill Medicare at all; every scan is fully private, regardless of the referral or indication.

The practical implication: an eligible indication on an ineligible machine still results in a full private fee. When cost matters to your patient, it is worth confirming that the clinic operates a Medicare-eligible machine for the item in question. Clinic reception staff can confirm this quickly, and directories such as Radly indicate bulk-billing and pricing information that reflects each clinic's licensing situation.

To give your patient the best chance of a rebate on an eligible indication:

• State the clinical indication in specific terms - the examination findings, symptom duration, and the diagnostic question, not just the symptom. • Include your provider number and the referral date; GP imaging referrals are valid for 12 months. • Specify the body part and laterality precisely. • Note relevant contraindications - implants, pacemakers, claustrophobia, renal impairment if contrast may be needed. • If you are unsure whether the indication qualifies, say so on the referral and ask the practice to advise - radiology booking staff deal with these descriptors daily.

If the indication clearly falls outside the GP-referrable items, consider whether a specialist referral is the better pathway, whether CT or ultrasound answers the question adequately, or whether the patient is willing to pay privately after an informed discussion.

Some MRI services attract a Medicare rebate only when requested by a specialist or consultant physician. Broad examples include cardiac MRI, MRI of the breast for high-risk surveillance (specific criteria apply), prostate MRI, and various staging and surveillance studies.

In these situations, referring the patient to the appropriate specialist first is usually faster and cheaper for the patient than a private GP-referred MRI, and the specialist can also interpret the result in the context of their management plan.

A sensible habit: before writing any MRI referral for an indication you don't request often, spend thirty seconds on MBS Online confirming whether the item is GP-referrable, specialist-only, or not listed. It is far easier than the alternative - an out-of-pocket surprise for the patient and a callback to your practice. This guide is general professional information; consult the current MBS and relevant guidelines for individual decisions.