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ICD-10 Guide
ICD-10 CodesA18

A18

Tuberculosis of other organs

BILLABLE STATUSNo
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 A18 is a used to indicate a diagnosis of tuberculosis of other organs.

Key Diagnostic Point:

Tuberculosis (TB) is primarily known as a pulmonary disease, but it can also affect other organs, leading to extrapulmonary tuberculosis. This condition occurs when the Mycobacterium tuberculosis bacteria spread from the lungs to other parts of the body, including the lymphatic system, bones, joints, kidneys, and even the central nervous system. Symptoms vary depending on the affected organ but may include fever, weight loss, night sweats, and localized pain. Diagnosis typically involves a combination of clinical evaluation, imaging studies such as X-rays or CT scans, and laboratory tests including sputum cultures and biopsies. Treatment usually consists of a prolonged course of antibiotics, often requiring a combination of drugs to combat potential drug resistance. Monitoring for treatment efficacy and side effects is crucial, as is adherence to public health protocols, including contact tracing and isolation procedures when necessary to prevent transmission. Drug-resistant TB is a significant concern, necessitating careful management and potentially more aggressive treatment regimens.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variety of affected organs leading to diverse symptoms.
  • Need for comprehensive diagnostic testing.
  • Potential for drug-resistant strains complicating treatment.
  • Variability in clinical presentation requiring careful assessment.

Audit Risk Factors

  • Inadequate documentation of the specific organ affected.
  • Failure to document the extent of disease.
  • Lack of clarity on the treatment regimen and adherence.
  • Insufficient follow-up documentation.

Specialty Focus

Medical Specialties

Infectious Disease

Documentation Requirements

Detailed clinical notes on symptoms, diagnostic tests, and treatment plans.

Common Clinical Scenarios

Patients presenting with unexplained fever, weight loss, or localized pain in areas such as the abdomen or bones.

Billing Considerations

Consideration of drug resistance and the need for specialized treatment regimens.

Pulmonology

Documentation Requirements

Comprehensive pulmonary assessments, including imaging and sputum analysis.

Common Clinical Scenarios

Patients with a history of TB presenting with respiratory symptoms or complications.

Billing Considerations

Coordination with infectious disease specialists for comprehensive management.

Coding Guidelines

Inclusion Criteria

Use A18 When
  • Follow the official ICD
  • CM coding guidelines, ensuring accurate documentation of the specific organ affected by tuberculosis
  • Include any relevant complications or co
  • morbidities

Exclusion Criteria

Do NOT use A18 When
  • Exclude codes for conditions that are not directly related to tuberculosis

Related Codes

Child Codes

37 codes
A18.0
Tuberculosis of bones and joints
A18.01
Tuberculosis of spine
A18.02
Tuberculous arthritis of other joints
A18.03
Tuberculosis of other bones
A18.09
Other musculoskeletal tuberculosis
A18.1
Tuberculosis of genitourinary system
A18.10
Tuberculosis of genitourinary system, unspecified
A18.11
Tuberculosis of kidney and ureter
A18.12
Tuberculosis of bladder
A18.13
Tuberculosis of other urinary organs
A18.14
Tuberculosis of prostate
A18.15
Tuberculosis of other male genital organs
A18.16
Tuberculosis of cervix
A18.17
Tuberculous female pelvic inflammatory disease
A18.18
Tuberculosis of other female genital organs
A18.2
Tuberculous peripheral lymphadenopathy
A18.3
Tuberculosis of intestines, peritoneum and mesenteric glands
A18.31
Tuberculous peritonitis
A18.32
Tuberculous enteritis
A18.39
Retroperitoneal tuberculosis
A18.4
Tuberculosis of skin and subcutaneous tissue
A18.5
Tuberculosis of eye
A18.50
Tuberculosis of eye, unspecified
A18.51
Tuberculous episcleritis
A18.52
Tuberculous keratitis
A18.53
Tuberculous chorioretinitis
A18.54
Tuberculous iridocyclitis
A18.59
Other tuberculosis of eye
A18.6
Tuberculosis of (inner) (middle) ear
A18.7
Tuberculosis of adrenal glands
A18.8
Tuberculosis of other specified organs
A18.81
Tuberculosis of thyroid gland
A18.82
Tuberculosis of other endocrine glands
A18.83
Tuberculosis of digestive tract organs, not elsewhere classified
A18.84
Tuberculosis of heart
A18.85
Tuberculosis of spleen
A18.89
Tuberculosis of other sites

Related CPT Codes

71046CPT Code

Chest X-ray, 2 views

Clinical Scenario

Used to evaluate for pulmonary involvement in TB.

Documentation Requirements

Document the reason for the X-ray and findings.

Specialty Considerations

Pulmonologists may order this as part of the initial workup.

88305CPT Code

Pathology examination of tissue

Clinical Scenario

Used when a biopsy is performed to confirm TB in affected organs.

Documentation Requirements

Document the site of biopsy and findings.

Specialty Considerations

Infectious disease specialists may coordinate this procedure.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of tuberculosis cases, enabling better tracking of disease prevalence and treatment outcomes. A18 provides a distinct code for extrapulmonary TB, which was less clearly defined in ICD-9.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of tuberculosis cases, enabling better tracking of disease prevalence and treatment outcomes. A18 provides a distinct code for extrapulmonary TB, which was less clearly defined in ICD-9.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of tuberculosis cases, enabling better tracking of disease prevalence and treatment outcomes. A18 provides a distinct code for extrapulmonary TB, which was less clearly defined in ICD-9.

Resources

Clinical References

  • •
    CDC Tuberculosis (TB) Fact Sheet

Coding & Billing References

  • •
    CDC Tuberculosis (TB) Fact Sheet

Frequently Asked Questions

What are the common symptoms of extrapulmonary tuberculosis?

Common symptoms include localized pain, fever, weight loss, and night sweats, which vary depending on the organ affected.

How is extrapulmonary tuberculosis diagnosed?

Diagnosis typically involves imaging studies, laboratory tests, and sometimes biopsies to confirm the presence of Mycobacterium tuberculosis.

What are the treatment options for extrapulmonary tuberculosis?

Treatment usually involves a multi-drug regimen over several months, with close monitoring for drug resistance and side effects.

What public health measures are necessary for tuberculosis?

Public health measures include contact tracing, isolation of infectious patients, and monitoring for drug-resistant strains.