Procedure Code Modifier

Key facts

Format

Two characters: numeric (CPT) or alphanumeric (HCPCS Level II)

CPT modifiers maintained by

American Medical Association (AMA)

HCPCS Level II modifiers maintained by

Centers for Medicare and Medicaid Services (CMS)

Limit per line

Up to four modifiers per service line on professional claims

What is a procedure code modifier?

A procedure code tells a payer what service was performed. A modifier adds context that the code descriptor cannot carry: that a procedure was done on both sides of the body, that a physician read an imaging study without owning the equipment, or that two services on the same day were truly separate.

Modifiers are reported next to the Current Procedural Terminology (CPT) or Healthcare Common Procedure Coding System (HCPCS) code on each claim line. Some change how much is paid. Others are informational or are needed to get a claim past automated edits.

Common types of modifiers

Modifiers fall into a few practical groups:

• Component modifiers: 26 (professional component) and TC (technical component) split services such as imaging into the interpretation and the equipment and staff portion.
• Anatomic modifiers: LT and RT (left and right side), 50 (bilateral procedure), and modifiers for specific fingers, toes and eyelids.
• Distinct service modifiers: 59 and the more specific XE, XS, XP and XU indicate a procedure was separate from another service billed the same day.
• Modifier 25: a significant, separately identifiable evaluation and management service on the same day as a procedure.
• Surgical team modifiers: 62 for co-surgeons, and 80, 82 and AS for assistants at surgery.
• Liability and drug modifiers: GA shows a required liability waiver, such as an Advance Beneficiary Notice of Noncoverage, is on file; JW and JZ report discarded or fully used drug from single-dose containers.

Why modifiers matter

Modifiers change both payment and the meaning of claims data. Medicare reduces payment for additional procedures in the same session and pays the professional and technical components of many diagnostic tests separately, so the same code can carry very different payment depending on its modifiers.

The National Correct Coding Initiative (NCCI) edits deny certain code pairs billed together unless an appropriate modifier is used. That is why modifiers 59 and 25 draw close attention in payer audits and in reviews by the HHS Office of Inspector General.

In claims analysis, ignoring modifiers can double count work. A radiologist billing the professional component and a facility billing the technical component can look like two studies when only one was performed.