M17.12 ICD-10-CM Code: Unilateral primary osteoarthritis, left knee
M17.12 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Osteoarthritis (M15-M19)
M17.12
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceUnilateral primary osteoarthritis, left knee
Osteoarthritis of the left knee that develops naturally over time as a result of aging and wear on the joint.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Primary osteoarthritis of knee NOSInherited from M17.1
Excludes 2
Official- arthropathic psoriasis (L40.5-)Inherited from M00-M99, M15-M19
- certain conditions originating in the perinatal period (P04-P96)Inherited from M00-M99, M15-M19
- certain infectious and parasitic diseases (A00-B99)Inherited from M00-M99, M15-M19
- compartment syndrome (traumatic) (T79.A-)Inherited from M00-M99, M15-M19
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from M00-M99, M15-M19
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from M00-M99, M15-M19
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from M00-M99, M15-M19
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from M00-M99, M15-M19
- neoplasms (C00-D49)Inherited from M00-M99, M15-M19
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from M00-M99, M15-M19
- osteoarthritis of spine (M47.-)Inherited from M00-M99, M15-M19
Related Codes
Includes
OfficialNo Includes notes are included in this display for M17.12. Check the code and parent instructions in the Code Book.
Excludes 1
OfficialNo Excludes 1 notes are included in this display for M17.12. Check the code and parent instructions in the Code Book.
Code First
OfficialNo Code First sequencing instructions are included in this display for M17.12. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for M17.12. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for M17.12. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is M17.12 an HCC code?
No. M17.12 is a billable ICD-10-CM code with no mapping under the current CMS-HCC V28 community payment model, and none under the ESRD, Part D RxHCC, or HHS-HCC models.
- Code
- M17.12
- Description
- Unilateral primary osteoarthritis, left knee
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF reference coefficient
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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What This Code Means
M17.12 is the ICD-10-CM diagnosis code for unilateral primary osteoarthritis, left knee. Osteoarthritis of the left knee that develops naturally over time as a result of aging and wear on the joint. M17.12 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering osteoarthritis (m15-m19).
M17.12 is a billable ICD-10-CM code, but no current CMS-HCC V28 community payment mapping is shown, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.
Confirm documentation indicates the left knee is the affected side and osteoarthritis is primary.
HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for M17.12 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm documentation indicates the left knee is the affected side and osteoarthritis is primary
- •This code provides clear laterality and should be used when the left knee is documented as affected