Use of Modifiers

20.6 - Use of Modifiers (Rev. 11937; Issued: 03-31-23; Effective: 04-01-23; Implementation: 04-03-23) Modifiers are two-digit identifiers that are reported with CPT and HCPCS Level II codes to provide additional information about how an item, procedure, or service is provided, and improve the accuracy of coding. These two-digit modifiers can be alphabetic, numeric, or a combination of both. The use of modifiers is not limited to certain code sets. Specifically, CPT modifiers may be used with HCPCS Level II codes when appropriate. Similarly, HCPCS Level II modifiers may be used with CPT codes to appropriately describe how an item, procedure, or service is provided. Providers may use any applicable modifier where appropriate. For Medicare purposes, modifiers are used either as pricing or informational/tracking indicators. The Integrated Outpatient Code Editor (I/OCE) accepts all valid CPT and HCPCS Level II modifiers on OPPS claims. As of April 1, 2023, there are approximately 410 active and valid modifiers. Definitions for all valid modifiers may be found in the latest CPT and HCPCS Level II code references. The complete descriptions for all CPT modifiers can be found in the latest CPT code book. Alternatively, the complete descriptions for the HCPCS Level II modifiers can be found in the latest HCPCS Level II code book, as well as in the latest HCPCS Level II code file that is available on the CMS HCPCS website, specifically, at https://www.cms.gov/medicare/coding/hcpcsreleasecodesets/hcpcs- quarterly-update. Additional guidance on the use of modifiers can also be found on the Medicare Administrative Contractors’ (MAC) websites. Note that, under the OPPS, the use of modifiers applies to services/procedures performed on the same calendar day. The following subsections provide information on the use of certain modifiers under the hospital OPPS. For information on additional modifiers not described below, refer to your MAC website(s) for guidance.