Eligibility check coverage

On almost every item in the Medicare Benefits Schedule (MBS), RebateRight gives a clear eligible or not eligible. On a small set of 178 items, 2.9% of the MBS, RebateRight can return cannot determine in place of a guess. Whether these items affect you depends on what you bill.

When you see cannot determine

The limit on how often an item can be claimed leads to cannot determine when all 4 of these are true at the same time:

• the patient is treated out of hospital
• the item is one of the 178 listed below
• the patient’s Medicare details are valid
• every other RebateRight check passes, such as the referral and the patient’s age

Any condition false. When any one of the 4 is false, you get eligible or not eligible with the reason, unless another check could not run. On these 178 items too, RebateRight flags a wrong Medicare detail, or a rule that finds the item not eligible, before the claim goes in.

All conditions true. When all 4 are true, cannot determine tells you the claim already clears everything RebateRight can check: the patient’s Medicare details matched, and every other check found the item eligible. What remains is how many times the item has already been claimed. For out-of-hospital claims, Services Australia does not share the patient’s claim history.

Other causes. cannot determine has other causes too, on any item, such as a missing referrer, mismatched patient details or a Medicare outage. Eligibility Check lists every cause and what to do.

See if your items are affected

Below are the 178 items as at the 1 November 2026 MBS, grouped by category. Open a category to browse its items.

These 3 MBS categories have none of the 178 items:

• Category 4 · Oral and maxillofacial services
• Category 7 · Cleft lip and palate services
• Category 10 · Child Dental Benefits Schedule

Indicative items

Services Australia verifies most MBS items live. For the rest, RebateRight applies the MBS rules itself and gives a clear eligible or not eligible. We call this an indicative result.

An indicative result comes from RebateRight’s own rules rather than a live Services Australia check. The response says so every time: the Frequency of service entry in Checks states that Medicare does not verify the item online.

The 178 items above are the indicative items that also limit how often they can be claimed. That limit is the one check that cannot be confirmed out of hospital, so on these items it leads to cannot determine.

Section 7 of the Software Licence Agreement covers indicative results.

Reciprocal Medicare cardholders

Patients covered by Australia’s Reciprocal Health Care Agreements (RHCAs) carry a reciprocal Medicare card. Reciprocal cardholders are entitled to medically necessary care while in Australia, under the same MBS item rules as a standard cardholder, including claim frequency limits.

Cover terms vary by country. Reciprocal Health Care Agreements on the Services Australia site and MBS note GN.3.9 set out the terms for each country.

Services Australia does not check these patients online, so Medicare returns no eligibility assessment for them.

RebateRight’s own rules still run, so an item can get a definite answer. Each item comes back:

• not eligible when one of our checks rules it out, such as patient age or in-hospital status. That answer stands on its own and needs no confirmation.
• cannot determine when all our rules pass, because the checks only Medicare can run have not taken place.

In both cases, Checks shows each check that ran and each one RebateRight could not reach.

For developers. For a reciprocal cardholder, PatientVerification.Verified is null. The entry for Medicare’s assessment in Checks has IsEligible: null and carries Medicare’s own sentence in Reason. The item’s IsEligible follows the 2 cases above.

For developers

The item list. Request every item from GET /MedicareItems, then keep the items where BenefitType is _85 or _100 and ClaimHistoryLimitation is not empty.

In an eligibility response. cannot determine is IsEligible: null. The unchecked limit appears in Checks as a Frequency of service entry with IsEligible: null.

When the limit applies. On these items, the limit makes the item IsEligible: null only on an out-of-hospital request where every other check finds the item eligible. When a check finds the item not eligible, the item is IsEligible: false with the reason. An in-hospital request returns the live result.

POST /CalculateRebate -> Rebates[]
{
  "ItemNumber": "701",
  "IsEligible": null,
  "Reason": "This item has a frequency-of-service limit, and Medicare doesn't verify it online for out-of-hospital claims. Without the patient's claim history, eligibility can't be determined.",
  "Benefit": "0"
}