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).
| Modifier | Description | Effective | |
|---|---|---|---|
| KX | Requirements specified in the medical policy have been met | Jul 01, 2002 | |
| KY | Dmepos item subject to dmepos competitive bidding program number 5 | Jan 01, 2008 | |
| KZ | New coverage not implemented by managed care | Oct 01, 2003 | |
| L1 | Provider attestation that the hospital laboratory test(s) is not packaged under the hospital opps | Jan 01, 2017 | |
| LC | Left circumflex coronary artery | Jan 01, 1997 | |
| LD | Left anterior descending coronary artery | Jan 01, 1997 | |
| LL | Lease/rental (use the 'll' modifier when dme equipment rental is to be applied against the purchase price) | Jan 01, 1997 | |
| LM | Left main coronary artery | Jan 01, 2013 | |
| LR | Laboratory round trip | Jan 01, 1997 | |
| LS | Fda-monitored intraocular lens implant | Jan 01, 1997 | |
| LT | Left side (used to identify procedures performed on the left side of the body) | Jan 01, 1997 | |
| LU | Fractionated payment | Apr 01, 2023 | |
| M2 | Medicare secondary payer (msp) | Jan 01, 2007 | |
| MA | Ordering professional is not required to consult a clinical decision support mechanism due to service being rendered to a patient with a suspected or confirmed emergency medical condition | Jan 01, 2025 | |
| MB | Ordering professional is not required to consult a clinical decision support mechanism due to the significant hardship exception of insufficient internet access | Jan 01, 2025 | |
| MC | Ordering professional is not required to consult a clinical decision support mechanism due to the significant hardship exception of electronic health record or clinical decision support mechanism vendor issues | Jan 01, 2025 | |
| MD | Ordering professional is not required to consult a clinical decision support mechanism due to the significant hardship exception of extreme and uncontrollable circumstances | Jan 01, 2025 | |
| ME | The order for this service adheres to appropriate use criteria in the clinical decision support mechanism consulted by the ordering professional | Jan 01, 2025 | |
| MF | The order for this service does not adhere to the appropriate use criteria in the clinical decision support mechanism consulted by the ordering professional | Jan 01, 2025 | |
| MG | The order for this service does not have applicable appropriate use criteria in the qualified clinical decision support mechanism consulted by the ordering professional | Jan 01, 2025 | |
| MH | Unknown if ordering professional consulted a clinical decision support mechanism for this service, related information was not provided to the furnishing professional or provider | Jan 01, 2025 | |
| MS | Six month maintenance and servicing fee for reasonable and necessary parts and labor which are not covered under any manufacturer or supplier warranty | Jan 01, 1997 | |
| N1 | Group 1 oxygen coverage criteria met | Jan 01, 2023 | |
| N2 | Group 2 oxygen coverage criteria met | Jan 01, 2023 | |
| N3 | Group 3 oxygen coverage criteria met | Jan 01, 2023 |