A procedure code followed by the modifier-99 indicates

• A. Primary modifiers
• B. One modifier
• C. Several modifiers
• D. Multiple modifiers

Answer: (D)

Modifier 99 signals that more than one modifier applies to the same procedure code. It acts as a flag that multiple modifiers accompany that single service, so you would attach -99 after listing the relevant modifiers to show there are several modifiers in total. It’s not about a single modifier or about primary modifiers; those concepts refer to individual modifier codes, whereas -99 indicates the presence of multiple modifiers. Some payers require documentation or have rules about using 99, but the core idea is that the code has multiple modifiers attached.