[Guides](/guides) The MBS multiple operation rule and surgical assistant fees =========================================================== Updated 28 October 2026 When one surgeon performs two or more operations on a patient on the one occasion, the fees are reduced under the **multiple operation rule**: **100%** of the largest schedule fee, **50%** of the next largest, and **25%** of each other. The reduced fees are added up and treated as one service, and Medicare and the health fund pay their benefits on that reduced total. The [cost estimate](/estimate) applies the rule automatically when you add two or more operations. Where the rule comes from ------------------------- The rule is in **section 15 of the Health Insurance Act 1973**. The MBS explanatory notes repeat it for each category of operations: ServicesNoteRuleGroup T8 surgical operations, except subgroup 12 (amputations)TN.8.2100% / 50% / 25%Groups O3 to O9 (oral and maxillofacial)ON.3.2100% / 50% / 25%Items 75200 to 75610 (cleft lip and palate)CN.0.8100% / 50% / 25%Items 82201 and 82202MN.14.19100% / 50% Amputations and disarticulations of a limb are excluded by section 15(4) and are paid in full. A worked example ---------------- A surgeon performs three operations under one anaesthetic: ItemSchedule feeRuleFee after the rule[51904](/items/51904)$544.40100%$544.40[45200](/items/45200)$340.3050%$170.15[30071](/items/30071)$62.5525%$15.65 The total is $730.20 rather than $947.25. In hospital, Medicare pays 75% of each reduced fee, and the fund pays at least the remaining 25%. **Rounding.** Each reduced amount that is not a multiple of 5 cents is rounded **up** to the next 5 cents: 25% of $62.55 is $15.6375, which becomes $15.65. The Act rounds each reduced fee; the MBS note talks about rounding the sum, but the Act prevails. **Equal fees.** If two items have the same fee, one is treated as the larger. When the rule does not apply ---------------------------- - **Different surgeons** operating independently: the rule applies to each surgeon’s own services, not across them. - **A return to theatre** on the same day for a post-operative complication is generally a separate occasion; endorse the account accordingly. - **Combined items:** where the MBS has one item for a combination of procedures, that item is the whole service. - **Items that can’t be claimed together** (“not being a service associated with…”) are not rescued by the rule; only one of them is claimable. The surgical assistant’s fee ---------------------------- An assistant can claim only for operations whose descriptor includes **“(Assist.)”**. To work out the fee, the multiple operation rule is applied again, to the assisted operations only (MBS note TN.9.1): - if the reduced total for the assisted operations is **$668.25 or less**, the assistant claims [item 51300](/items/51300) ($103.25); - above that, the assistant claims [item 51303](/items/51303) at **one fifth** of the reduced total. > In the example above, all three items would need “(Assist.)” to count. If only 51904 does, the assisted total is $544.40, so the assistant claims 51300. Only one assistant benefit is paid, however many people assist, and the assistant can’t be the surgeon or anaesthetist. Anaesthesia ----------- The anaesthetist does not use the multiple operation rule. Anaesthesia is billed on the Relative Value Guide: basic units for the procedure, time units (15 minutes each for the first two hours, then 10 minutes), and modifying units for the patient’s physical status, age or an emergency. Each unit is worth **$23.70** from 1 July 2026. Frequently asked questions -------------------------- ### What is the multiple operation rule? When one practitioner performs two or more operations on a patient on the one occasion, the largest schedule fee is paid at 100%, the next largest at 50% and every other at 25%. The reduced fees are added together and treated as one service. ### Which MBS items does the multiple operation rule apply to? Group T8 surgical operations other than amputations, Groups O3 to O9, items 75200 to 75610, and items 82201 and 82202, which use 100% and 50% only. ### How is the multiple operation rule rounded? Each reduced fee that is not a multiple of 5 cents is rounded up to the next multiple of 5 cents, as section 15(2) of the Health Insurance Act requires. The reduced fees are then added together. ### Does the multiple operation rule apply when two surgeons operate? Not across surgeons. If two surgeons operate independently, the rule is applied to each surgeon’s own operations separately. ### How is the surgical assistant’s fee calculated for multiple operations? Apply the multiple operation rule to the operations marked “(Assist.)” only. If that total is $668.25 or less, the assistant claims item 51300 at $103.25; otherwise item 51303 at one fifth of the total. More guides ----------- - [How Medicare benefits work: schedule fees, 75%, 85% and 100%](/guides/how-medicare-benefits-work) - [Medicare safety nets explained: original and extended (EMSN) thresholds for 2026](/guides/medicare-safety-nets) - [In-hospital billing: the 75% benefit, the 25% fund benefit, and no-gap and known-gap schemes](/guides/in-hospital-billing-and-gap-cover) - [Bulk billing incentives and BBPIP explained: 2026 amounts by MM area](/guides/bulk-billing-incentives) - [Assignment of benefit for bulk billing: the changes from 1 July 2026](/guides/assignment-of-benefit-2026) - [MBS telehealth rules: the eligible telehealth practitioner and phone items](/guides/mbs-telehealth-rules) - [GP chronic condition management plans: items 965 and 967 explained](/guides/chronic-condition-management-plans) - [Medicare billing compliance: claim time limits, records and the 80/20 rule](/guides/medicare-billing-compliance) General information for health professionals, not legal or financial advice. Check MBS Online and Services Australia for the rules that apply to your circumstances.