Modifier 99

Multiple Modifiers (same line, same code)


When more than four modifiers are needed to describe a service on the same code, replace with modifier 99.

Correct Use

  • Reflect all modifiers involved in Item 19 narrative or electronic equivalent
    • Replace with modifier 99 in Item 24D
    • Documentation must explain all modifiers involved
    • Includes informational and pricing modifiers
    • Certain modifiers may affect payment

Incorrect Use

  • In this situation, do not append other modifiers in Item 24D

Claim Coding Example

Patient had a Mohs removal (within 90 day global) on the left cheek and then another on the right cheek (RT) by the same provider, repeated twice (i.e., 79, 59, RT) and not enough modifier spaces.

Treatment Description CPT/Modifier
Mohs micrographic technique, including removal 17311 99




Last Updated Dec 09 , 2023