M01.X9 — Direct infection of multiple joints in infectious and parasitic diseases classified elsewhere

BillableCC

Is M01.X9 billable?

Yes — M01.X9 is billable for FY2027. M01.X9 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. M01.X9 may be submitted for encounters from October 1, 2026 through September 30, 2027.

M01.X9 at a glance

Code	M01.X9
Description	Direct infection of multiple joints in infectious and parasitic diseases classified elsewhere
Billable	Yes
Code set	ICD-10-CM FY2027
Valid for encounters	October 1, 2026 – September 30, 2027

What Medicare edits apply to M01.X9?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M01.X9 directly.

Manifestation code — never sequenced first — MCE edit 6

This code describes a manifestation of an underlying disease. The underlying condition must be sequenced before it, so it can never be the principal or first-listed diagnosis.

Which MS-DRGs does M01.X9 group to?

M01.X9 sits in MDC 08 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

548Septic Arthritis with MCCmedical
549Septic Arthritis with CCmedical
550Septic Arthritis without CC/MCCmedical

As a secondary diagnosis, M01.X9 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

Excludes1 — never code together — inherited from M01

The conditions below can never be reported together with M01.X9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

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)

Code first — inherited from M01

The underlying condition below must be sequenced before M01.X9. M01.X9 describes a manifestation and cannot be the principal or first-listed diagnosis.

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

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M01.X9, but a patient may have both at the same time. When documentation supports it, M01.X9 and the excluded code may both be reported.

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)

How long has M01.X9 existed?

M01.X9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.