How should modifier 91 be reported under the National Correct Coding Initiative (NCCI) program?


Modifier 91 may be appended to laboratory procedure(s) or service(s) to indicate a repeat test or procedure on the same day when appropriate. This modifier indicates to the Medicare contractors that the physician had to perform a repeat clinical diagnostic laboratory test that was distinct or separate from a lab panel or other lab services performed on the same day, and was performed to obtain medically necessary subsequent reportable test values. It must not be used to report repeat laboratory testing due to laboratory errors, quality control, or confirmation of results.


CPT® copyright 2021 American Medical Association (AMA). All rights reserved.

Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.

CPT is a registered trademark of the American Medical Association.