2026 ICD-10-CM Diagnosis Code A18.02Tuberculous arthritis of other joints

ICD-10-CM Codes›A00–B99›A15-A19›A18

ICD-10-CM A18.02
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A18.02 is a billable ICD-10-CM diagnosis code for tuberculous arthritis of other joints. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 485 through 487, 548 through 550, 974 through 976. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 1 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Infective arthritis and Tuberculosis.

Code Identity

ICD-10-CM Code
A18.02
Billable Status
Yes — Valid for Submission
Code Describes
Tuberculous arthritis of other joints
Short Description
Tuberculous arthritis of other joints
Same as the full description in the CMS dataset.
Parent Code
A18.0
Tuberculosis of bones and joints

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA15-A19Tuberculosis
CategoryA18Tuberculosis of other organs
This CodeA18.02Tuberculous arthritis of other joints

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthritis of bilateral knee joints caused by bacteria
  • Arthritis of left knee caused by bacteria
  • Arthritis of right knee caused by bacteria
  • Bilateral infective arthritis of knees
  • Infection of musculoskeletal system caused by Mycobacterium tuberculosis
  • Tuberculosis of bilateral knee joints
  • Tuberculosis of bones and/or joints
  • Tuberculosis of hip
  • Tuberculosis of knee
  • Tuberculosis of left knee joint
  • Tuberculosis of right knee joint
  • Tuberculous arthritis
  • Tuberculous arthritis of hand caused by Mycobacterium tuberculosis
  • Tuberculous arthritis of shoulder region caused by Mycobacterium tuberculosis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Tuberculosis of hip (joint)
  • Tuberculosis of knee (joint)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MUS001
Infective arthritis
Default principal diagnosis: inpatient No · outpatient No
CCSR INF001
Tuberculosis
Default principal diagnosis: inpatient Yes · outpatient Yes

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:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert A18.02 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
015.10 TB of hip-unspec
Approximate The match is approximate rather than exact.
ICD-9-CM
015.20 TB of knee-unspec
Approximate The match is approximate rather than exact.
ICD-9-CM
015.80 TB of joint NEC-unspec
Approximate The match is approximate rather than exact.
ICD-9-CM
015.90 TB bone/joint NOS-unspec
Approximate The match is approximate rather than exact.
ICD-9-CM
015.10 TB of hip-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
711.45 Bact arthritis-pelvis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
015.20 TB of knee-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
711.46 Bact arthritis-l/leg
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
015.80 TB of joint NEC-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
711.48 Bact arthritis NEC
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A18.02Overview

What is the ICD-10 code for tuberculous arthritis of other joints?

The ICD-10-CM code for tuberculous arthritis of other joints is A18.02 (sometimes written as A1802). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is A18.02 (Tuberculosis of bones and joints) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report tuberculous arthritis of other joints on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A18.02 group to?

When tuberculous arthritis of other joints is the principal diagnosis on an inpatient stay, it groups to MS-DRG 485, 486, 487, 548, 549, 550, 974, 975, 976, with relative weights from 0.8741 to 3.2271 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A18.02 a CC or MCC?

CMS lists A18.02 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 1 closely related codes in its exclusion list.

What is the ICD-9 equivalent of A18.02?

Under the General Equivalence Mappings, tuberculous arthritis of other joints converts to ICD-9-CM 015.10 (TB of hip-unspec), 015.20 (TB of knee-unspec), and 015.80 (TB of joint NEC-unspec). The mapping is approximate, so confirm the match fits the documentation.