AAMI Standards - Requirements vs Recommendations

AAMI Standards  |  The Sterile Guy

The Association for the Advancement of Medical Instrumentation (AAMI) is a standards development organization that provides guidelines and recommendations for the healthcare industry covering all medical device disinfection and sterilization processes. When reading through AAMI standards, it could be confusing at times to interpret the actual requirement your Sterile Processing department must follow. AAMI uses three distinct words that sometimes bring confusion when reading from a standards perspective.

AAMI defines certain terms, such as "may," "shall," and "should," within its standards to establish varying levels of requirements or recommendations. Let me break down these words and their true definitions according to AAMI.


When AAMI uses the term "may" in its standards, it indicates an optional action or possibility. It implies that a particular course of action or condition is allowed but not mandatory. It grants flexibility or discretion to the user or organization to decide whether to implement the suggested action. When AAMI uses the term "may", it is usually to provide flexibility to the end users with options. For instance, AAMI denotes eye protection as a requirement, but then states "which may include goggles, full-length face shields, or other devices." AAMI is not mandating any specific product, however, they do mandate eye protection.


The term "shall" in AAMI standards indicates a mandatory requirement. It imposes an obligation or a necessary action that must be followed without exception. It signifies a specific rule or provision that must be adhered to for compliance with the standard. The funny thing is though, the word "shall" is only mentioned in AAMI ST79:2017 two times. Once, in the explanation of what the word means in AAMI, and the second is only stating: “An integrating indicator shall be designed to react to all critical variables" in reference to how an integrating indicator works. With the amount of regulations in healthcare, it is mind boggling that the word shall is hardly used.


AAMI uses the term "should" to express a strong recommendation or sometimes even best practice. It suggests an action that is highly advisable to achieve the desired outcome but does not state it is mandatory. Deviation from a "should" recommendation may require a valid justification and usually opens the door to liability and findings from your hospital accreditation agency.

Strong Recommendation Example: "Biological indicators should be used within PCDs (see 13.5.4,,, and for routine sterilizer efficacy monitoring at least weekly." At least weekly is the absolute minimum and is not considered "best practice."

Best Practice Example: "Newly manufactured loaned items should be decontaminated before sterilization to remove bioburden and substances (e.g., oil, grease) that may remain on the item from the manufacturing process."

It's important to note that the definitions of these terms may vary slightly depending on the context or specific AAMI standard being referenced. It's essential to consult the relevant AAMI standard document for precise definitions and usage within a particular guideline or recommendation. These can be found in the "Forward" sections of the AAMI guidelines.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.