HCPCS Level II Modifiers

Two-character modifiers append to a procedure code to report that a service was altered in some way without changing its definition — a bilateral procedure, a distinct encounter, or a service performed by a specific provider type.

This registry contains the supported CMS-published HCPCS Level II modifier information. CPT modifier descriptors are not reproduced, and payer-specific modifier rules are outside its scope — not every modifier rule every payer applies is represented here.