M01.X69Direct infection of unspecified knee in infectious and parasitic diseases classified elsewhere

M01.X69 is the ICD-10-CM diagnosis code for direct infection of unspecified knee in infectious and parasitic diseases classified elsewhere. It belongs to category M01 (direct infections of joint in infectious and parasitic diseases classified elsewhere), block M00-M02 (infectious arthropathies) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within M01.X6, choose M01.X69 (unspecified knee in infectious and parasitic diseases classified elsewhere) only when documentation doesn't support a more specific option: right knee in infectious and parasitic diseases classified elsewhere (M01.X61) and left knee in infectious and parasitic diseases classified elsewhere (M01.X62).

Code first underlying disease, such as: leprosy [Hansen's disease] (A30.-), mycoses (B35-B49), O'nyong-nyong fever (A92.1) and paratyphoid fever (A01.1-A01.4).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 400 (Knee Procedures with Principal Diagnosis of Infection, relative weight 2.0248), DRG 548 (Septic Arthritis with MCC, relative weight 1.9519), DRG 549 (Septic Arthritis with CC, relative weight 1.1435) and DRG 550 (Septic Arthritis without CC/MCC, relative weight 0.8591), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

It is an unspecified code for which a more specific option (often laterality) exists, and the Medicare Code Editor flags it for review on inpatient claims.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 711.46 (arthropathy associated with other bacterial diseases, lower leg), 711.56 (arthropathy associated with other viral diseases, lower leg), 711.66 (arthropathy associated with mycoses, lower leg) and 2 more.