By Jennifer Frank and Anna Marie Jilla This article is a part of the September/October 2019, Volume 31, Number 5, Audiology Today issue. Billing modifiers were created to provide additional information to the payer about the performed procedure(s) and help describe and/or qualify the services provided. There are common modifiers used by commercial payers and the Centers for Medicare and Medicaid Services (CMS), that indicate to the payer that the services provided have been altered in a way that is different than the ascribed definition of the billing code. For example, a modifier should be used when all of the tests in a bundled code were not performed or when only one ear was tested. Additionally, modifiers are also used to indicate how non-covered services are handled for a specific claim. Coding requirements for current procedural terminology (CPT) modifiers can vary among payers, whereas some may not recognize certain modifiers. For tracking purposes and billing compliance, it is still necessary to supplement a billing code with a modifier when there is a change to the overall definition of the procedure or if procedures are considered non-covered services by CMS. The information in the tables provided is applicable to Medicare claims. Persons involved in submitting claims to Medicaid or payers other than CMS should gather state- or payer-specific information on the use of modifiers. The following tables and Q&As will provide guidance on when and why to use the different ascribed modifiers. This content is an exclusive benefit for American Academy of Audiology members. If you're a member, log in and you'll get immediate access. Member Login If you're not yet a member, you'll be interested to know that joining not only gives you access to top-notch resources like this one, but also invitations to member-only events, inclusion in the member directory, participation in professional forums, and access to patient resources, tools, and continuing education. Join today!