How to Bill for Anaesthetic Services: A Complete Guide for Anaesthetists

For anaesthetists in private practice, understanding how to bill for anaesthetic services is essential—not only for receiving payment, but also for ensuring compliance and maintaining professionalism. Unlike salaried or bulk-billed models, private anaesthetic billing requires you to know how to apply time units, ASA classifications, Medicare rules, and informed financial consent. Yet for many anaesthetists—especially early in their careers—billing feels confusing, time-consuming, or simply overwhelming.

This guide has been written specifically for anaesthetists in Australia who want to understand anaesthetic billing from the ground up. Whether you’re just starting or you’re reviewing your systems after years in practice, this page is your go-to reference.

how to bill for anaesthetic services

How to Bill for Anaesthetic Services: Step-by-Step Breakdown

Anaesthetic billing in Australia is based on a unit system. Each anaesthetic service is calculated by combining:

  • Base units (assigned to each surgical procedure)
  • Time units (one unit for every 15 minutes of anaesthesia time)
  • ASA modifier (one extra unit for ASA 3 or 4 patients)
  • Other modifiers (e.g., emergency loading, after-hours)

Each unit has a monetary value determined by your fee schedule (e.g., $50–$100 per unit, depending on location and fund agreements).

Example: Providing Anaesthesia for Ear Surgery

To calculate the total fees for ear surgery that takes 70 minutes, and with a patient with a severe systemic disease, the following would be invoiced (based on a charge of $60 per unit):

  • MBS Code 20120 / Base units: 5
  • Time: 70 mins = 5 time units
  • ASA 3 = +1 unit
  • Total: 11 units x $60 = $660

Billing correctly ensures you’re paid fairly and that your patient receives appropriate disclosure and documentation.

Understanding ASA Scores

ASA (American Society of Anesthesiologists) scores indicate the preoperative physical status of a patient.

  • ASA 1: Normal healthy patient
  • ASA 2: A patient with a mild systemic disease
  • ASA 3: A patient with a severe systemic disease
  • ASA 4: A patient with a severe systemic disease at constant threat to life

Only ASA 3 and above add extra billing units (one for ASA 3 and two for ASA 4). But this must be justifiable—and increasingly, health funds are asking for notes to match the classification.

Tip: Document the score and include supporting details (e.g., “ASA 3 due to COPD + BMI >35”) in the anaesthetic record.

Example Case:

A 67-year-old male with obstructive sleep apnoea, diabetes, and hypertension undergoing hip replacement may be appropriately classified as ASA 3, provided these comorbidities impact perioperative risk.

Informed Financial Consent (IFC)

Before billing a private patient, it is your legal and ethical obligation to provide Informed Financial Consent. This should:

  • Outline the estimated fee
  • Explain any out-of-pocket costs
  • Be provided at least 2 business days before the procedure

IFC is not just best practice—it protects your reputation and income. Patients appreciate clarity, especially when out-of-pocket fees are involved. Written consent, or even email confirmation, is strongly advised.

Need Help Sending IFCs and Billing Accurately?

At Fast Tracking Anaesthetic Billing Services, we manage:

  • IFC preparation and delivery
  • Accurate item number selection
  • Submission to health funds, Medicare and DVA
  • Rejection follow-up

Let us take the stress out of billing so you can focus on your patients.

MBS Item Numbers: Choosing the Right One

Each surgical procedure has a corresponding anaesthetic item number. Your base unit depends on selecting the correct code.

To get it right:

  • Ask the surgeon for the item number of the operation
  • Match the correct anaesthetic code from the MBS

The most common errors we see come from guessing or using a previous code that doesn’t match the current surgery.

Time Units: Start to Finish Matters

You receive one unit for every 15 minutes of anaesthesia. This includes:

  • Pre-oxygenation
  • Induction
  • Surgical time
  • Emergence and post-op handover

Accurate time recording avoids underbilling and ensures compliance.

Tip: Write start and finish times clearly on your anaesthetic record and make sure they match theatre logs if requested.

avoiding billing mistakes

Avoiding Common Billing Mistakes

Here are some common pitfalls:

  • Forgetting to add the ASA modifier for eligible patients
  • Using the wrong item number for the procedure
  • Failing to issue an IFC (especially when a gap is involved)
  • Billing the fund when the patient has no coverage
  • Not following up on unpaid claims

These errors can cost you hundreds or even thousands over time.

Billing in Public vs Private Settings

In public hospitals, anaesthetic billing is generally not applicable unless you’re servicing a private patient with their own cover. If you’re unsure how to bill for anaesthetic services in public settings, always confirm whether the patient has been formally booked as a private case.

In private hospitals:

  • You must provide IFC
  • You may bill the fund, Medicare, or the patient directly (depending on the model)
  • Ensure that you sign up to health fund schemes, that you abide by their terms in regards to out of pocket expenses for patients.

Even when a patient is in a public facility, if they’re privately insured and booked as a private case, billing is permitted and expected. Understanding how to bill for anaesthetic services in mixed environments ensures you’re compliant with fund rules and hospital policy.

Should You Use a Billing Service?

If billing is taking more than 1–2 hours a week, or you’re struggling with rejections or patient admin, the answer is likely yes.

A professional billing provider will:

  • Ensure correct units and item codes
  • Issue IFC and reminders
  • Lodge claims quickly
  • Chase up unpaid accounts
  • Provide monthly reporting for BAS, tax, or forecasting

You didn’t train as a specialist to spend your evenings emailing IFCs or chasing payments. Outsourcing frees up time and reduces stress.

Want Your Billing Done For You?

Our team at Fast Tracking Anaesthetistic Billing Services helps Australian anaesthetists keep billing smooth, fast, and compliant.

  • No lock-in contracts
  • Transparent reporting
  • Supportive admin for your patients

Final Thoughts

Anaesthetic billing isn’t something you should feel unsure about. When done correctly, it supports your financial security and ensures your patients understand what to expect.

Whether you choose to do it yourself or delegate, the key is accuracy, consistency, and compliance.

This guide is your starting point, but your billing process deserves personalisation.

If you’d like expert eyes on your current system, or want someone to take over the admin entirely, Fast Tracking Anaesthetic Billing Services is here to help.

If you’re looking for a full-service billing partner, visit our anaesthetic billing service page.