In simple words: This code is used to track how well your knee is functioning after surgery, using scores from questionnaires taken approximately one year after the operation.

This code documents the patient's functional status was measured between nine and 15 months after knee surgery and was less than 37 as determined by the patient's report using the Oxford Knee Score (OKS), or the functional status was less than 71 based on the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR.).

Example 1: A patient underwent total knee arthroplasty 12 months prior. The patient completed the Oxford Knee Score (OKS) questionnaire, and their score is 32. This code (M1046) is reported to indicate the functional status measurement., A patient is 10 months post-op from total knee replacement surgery. They complete the KOOS, JR. questionnaire, scoring 65. M1046 is reported for quality measure reporting., 14 months after knee surgery, the patient reports their knee function using the OKS, with a result of 42. While the score is above the threshold of 37, the M1046 can be reported.

The documentation should include the date of the functional assessment, the type of assessment tool used (OKS or KOOS, JR.), and the resulting score.

** HCPCS Level II codes starting with "M" are typically used by providers participating in Medicare quality payment programs (QPP) like MIPS or APM.