M01.X12
Direct infection of left shoulder in infectious and parasitic diseases classified elsewhere
M01.X12 (also written M01X12) is a billable ICD-10-CM diagnosis code for direct infection of left shoulder in infectious and parasitic diseases classified elsewhere. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 24 codes in category M01 (Direct infections of joint in infectious and parasitic diseases classified elsewhere). Its coding notes include a Code first instruction, 11 Excludes1 entries and 10 Excludes2 entries.
Code first
If the underlying condition listed here is present and known, sequence it first.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- arthropathy in Lyme disease (A69.23)
- gonococcal arthritis (A54.42)
- meningococcal arthritis (A39.83)
- mumps arthritis (B26.85)
- postinfective arthropathy (M02.-)
- postmeningococcal arthritis (A39.84)
- reactive arthritis (M02.3)
- rubella arthritis (B06.82)
- sarcoidosis arthritis (D86.86)
- typhoid fever arthritis (A01.04)
- tuberculosis arthritis (A18.01-A18.02)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (10 notes)
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospice: not accepted as primary
Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Manifestation code. Report the underlying condition first (see the Code first note).
Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 938 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CNotes
Also from chapter/block level (4 notes)
- This block comprises arthropathies due to microbiological agents. Distinction is made between the following types of etiological relationship:
- a) direct infection of joint, where organisms invade synovial tissue and microbial antigen is present in the joint;
- b) indirect infection, which may be of two types: a reactive arthropathy, where microbial infection of the body is established but neither organisms nor antigens can be identified in the joint, and a postinfective arthropathy, where microbial antigen is present but recovery of an organism is inconstant and evidence of local multiplication is lacking.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition