Doctors should steer clear of following advice from so-called Medicare billing gurus because so many MBS rules are vague, incomprehensible and ambiguous, researchers are warning.

In recent years, there has been a dramatic growth in the number of companies and expert advisers offering guidance on how to best navigate Medicare — particularly as doctors and practices struggle under limited rebates.

But much of the information shared is potentially incorrect, warn academics from the University of Technology Sydney.

They point to the rise of Business for Doctors, a closed Facebook group with 24,000 members seeking answers about billing and medical finance.