HCPCS Modifiers List

A modifier provides the means by which the reporting physician or provider can indicate that a service or procedure that has been performed has been altered by some specific circumstance but not changed in its definition or code.

Level I modifiers are codes and descriptors copyrighted by the American Medical Association's current procedural terminology (CPT).

Level II modifiers are codes and descriptors approved and maintained jointly by the alpha-numeric editorial panel (consisting of CMS, the Health Insurance Association of America, and the Blue Cross and Blue Shield Association).

Modifiers may be used to indicate to the recipient of a report that:

A service or procedure has both a professional and technical component.
A service or procedure was performed by more than one physician and/or in more than one location.
A service or procedure has been increased or reduced.
Only part of a service was performed.
An adjunctive service was performed.
A bilateral procedure was performed.
A service or procedure was provided more than once.
Unusual events occurred.

Modifier	Description	Effective
CM	At least 80 percent but less than 100 percent impaired, limited or restricted	Jan 01, 2013
CN	100 percent impaired, limited or restricted	Jan 01, 2013
CO	Outpatient occupational therapy services furnished in whole or in part by an occupational therapy assistant	Jan 01, 2019
CP	Adjunctive service related to a procedure assigned to a comprehensive ambulatory payment classification (c-apc) procedure, but reported on a different claim	Jan 01, 2018
CQ	Outpatient physical therapy services furnished in whole or in part by a physical therapist assistant	Jan 01, 2019
CR	Catastrophe/disaster related	Aug 21, 2005
CS	Cost-sharing waived for specified covid-19 testing-related services that result in and order for or administration of a covid-19 test and/or used for cost-sharing waived preventive services furnished via telehealth in rural health clinics and federally qualified health centers during the covid-19 public health emergency	Mar 01, 2020
CT	Computed tomography services furnished using equipment that does not meet each of the attributes of the national electrical manufacturers association (nema) xr-29-2013 standard	Jan 01, 2016
DA	Oral health assessment by a licensed health professional other than a dentist	Jan 01, 2011
E1	Upper left, eyelid	Jan 01, 1999
E2	Lower left, eyelid	Jan 01, 1999
E3	Upper right, eyelid	Jan 01, 1999
E4	Lower right, eyelid	Jan 01, 1999
EA	Erythropoietic stimulating agent (esa) administered to treat anemia due to anti-cancer chemotherapy	Jan 01, 2008
EB	Erythropoietic stimulating agent (esa) administered to treat anemia due to anti-cancer radiotherapy	Jan 01, 2008
EC	Erythropoietic stimulating agent (esa) administered to treat anemia not due to anti-cancer radiotherapy or anti-cancer chemotherapy	Jan 01, 2008
ED	Hematocrit level has exceeded 39% (or hemoglobin level has exceeded 13.0 g/dl) for 3 or more consecutive billing cycles immediately prior to and including the current cycle	Jan 01, 2008
EE	Hematocrit level has not exceeded 39% (or hemoglobin level has not exceeded 13.0 g/dl) for 3 or more consecutive billing cycles immediately prior to and including the current cycle	Jan 01, 2008
EJ	Subsequent claims for a defined course of therapy, e.g., epo, sodium hyaluronate, infliximab	Jan 01, 2000
EM	Emergency reserve supply (for esrd benefit only)	Jan 01, 1997
EP	Service provided as part of medicaid early periodic screening diagnosis and treatment (epsdt) program	Jan 01, 1997
ER	Items and services furnished by a provider-based, off-campus emergency department	Jan 01, 2019
ET	Emergency services	Jan 01, 2002
EX	Expatriate beneficiary	Apr 01, 2015
EY	No physician or other licensed health care provider order for this item or service	Jan 01, 2003