What is an Assignment of Benefits (AOB) in Medical Billing?

This term refers to insurance payments made directly to a healthcare provider for medical services received by the patient. Assignment of benefits occurs after a claim has been successfully processed with an insurance company.

As Assignment of Benefits (often abbreviated to AOB) simply means that the patient is asking for their payment of their health benefits to be transferred to the doctor to used as payment.

In some medical offices, there is a form known as an ‘Assignment of Benefits’ that allows the patient to transfer these benefits automatically. This reduces the need to bill a fee for service on each transaction, which can be appealing to some patients.

Typically, providers or types of services listed below must accept assignment of benefits:

  • Clinical diagnostic laboratory services;
  • Physician services to individuals dually entitled to Medicare and Medicaid;
  • Services of physician assistants, nurse practitioners, clinical nurse specialists, nurse midwives, certified registered nurse anesthetists, clinical psychologists, and clinical social workers;
  • Ambulatory surgical center services for covered ASC procedures;
  • Home dialysis supplies and equipment paid under Method II;
  • Ambulance services;
  • Drugs and biologicals; and
  • Simplified Billing Roster for influenza virus vaccine and pneumococcal vaccine. 

It is important to note that not every patient has the contracted right to do so. Even if the patient signs as AOB form, the insurance company may not have to honor it if the patient cannot contractually assign their rights to anyone.

As a medical office it is important to understand most of the core insurance plans your office works with and how the patients benefits are typically paid.