ICD-10-CM 2027
ICD-10 code for infrapatellar fat pad fibrosis
From the official ICD-10-CM alphabetic index entry “Fibrosis, fibrotic › infrapatellar fat pad”. Page updated September 29, 2026.
About coding infrapatellar fat pad fibrosis
The ICD-10-CM code for infrapatellar fat pad fibrosis is M79.4 (Hypertrophy of (infrapatellar) fat pad).
Within M79 (other and unspecified soft tissue disorders, not elsewhere classified), M79.4 is specifically for hypertrophy of (infrapatellar) fat pad. Related codes cover rheumatism, unspecified (M79.0), myalgia (M79.1), neuralgia and neuritis, unspecified (M79.2), panniculitis, unspecified (M79.3), residual foreign body in soft tissue (M79.5), pain in limb, hand, foot, fingers and toes (M79.6), Fibromyalgia (M79.7), other specified soft tissue disorders (M79.8) and 2 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 606 (Minor Skin Disorders with MCC, relative weight 1.5728) and DRG 607 (Minor Skin Disorders without MCC, relative weight 0.8772), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about infrapatellar fat pad fibrosis ICD-10 codes
What is the ICD-10 code for infrapatellar fat pad fibrosis?
- M79.4 — Hypertrophy of (infrapatellar) fat pad.
Is M79.4 billable?
- Yes. M79.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M79.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M79.4 as a principal diagnosis.
Is M79.4 a CC or MCC?
- No. M79.4 is neither a CC nor an MCC under MS-DRG v44.0.