2026 ICD-10-CM Diagnosis Code M01.X9Direct infection of multiple joints in infectious and parasitic diseases classified elsewhere
ICD-10-CM Codes›M00–M99›M00-M02›M01
- Billable — Valid for Submission
- Not Chronic
M01.X9 is a billable ICD-10-CM diagnosis code for direct infection of multiple joints in infectious and parasitic diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 548 through 550. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Infective arthritis.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for M01.X9.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Infectious Arthritis
Most kinds of arthritis cause pain and swelling in your joints. Joints are places where two bones meet, such as your elbow or knee. Infectious arthritis is an infection in the joint. The infection comes from a bacterial, viral, or fungal infection that spreads from another part of the body. Symptoms of infectious arthritis include:
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Convert M01.X9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M01.X9Overview
Is M01.X9 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report direct infection of multiple joints in infectious and parasitic diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M01.X9 group to?
On inpatient claims, direct infection of multiple joints in infectious and parasitic diseases classified elsewhere maps to MS-DRG 548, 549, 550, with relative weights from 0.8741 to 1.9309 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M01.X9 be a principal diagnosis?
No. This is a manifestation code: direct infection of multiple joints in infectious and parasitic diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of M01.X9?
Under the General Equivalence Mappings, direct infection of multiple joints in infectious and parasitic diseases classified elsewhere converts to ICD-9-CM 711.49 (bact arthritis-mult), 711.59 (viral arthritis-mult), and 711.69 (mycotic arthritis-mult). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
