2027 ICD-10-CM Diagnosis Code A17.9Tuberculosis of nervous system, unspecified

ICD-10-CM Codes›A00–B99›A15-A19›A17

ICD-10-CM A17.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A17.9 is a billable ICD-10-CM diagnosis code for tuberculosis of nervous system, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869, 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 14 closely related codes. Coders also document this condition as tuberculosis of central nervous system. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (neither hereditary nor degenerative) and Tuberculosis.

Code Identity

ICD-10-CM Code
A17.9
Billable Status
Yes — Valid for Submission
Code Describes
Tuberculosis of nervous system, unspecified
Short Description
Tuberculosis of nervous system, unspecified
Same as the full description in the CMS dataset.
Parent Code
A17
Tuberculosis of nervous system

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA15-A19Tuberculosis
CategoryA17Tuberculosis of nervous system
This CodeA17.9Tuberculosis of nervous system, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Tuberculosis of central nervous system

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A17.9: its own notes plus those printed at block A15-A19 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block A15-A19 Tuberculosis applies to 51 codes
  • infections due to Mycobacterium tuberculosis and Mycobacterium bovis
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block A15-A19 Tuberculosis applies to 51 codes
  • congenital tuberculosis (P37.0)
  • nonspecific reaction to test for tuberculosis without active tuberculosis (R76.1-)
  • pneumoconiosis associated with tuberculosis, any type in A15 (J65)
  • positive PPD (R76.11)
  • positive tuberculin skin test without active tuberculosis (R76.11)
  • sequelae of tuberculosis (B90.-)
  • silicotuberculosis (J65)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Block A15-A19 Tuberculosis applies to 51 codes
  • code, if applicable, for associated cachexia (E88.A)
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A17.9, its category, or a range that includes it.

Applicable To 1

These notes mention A17.9.

  • O98.0 Tuberculosis complicating pregnancy, childbirth and the puerperium
    Conditions in A15-A19 names A15-A19, which includes this code

Excludes2 1

These codes carry an Excludes2 note naming A17.9: its condition is not part of those codes, and both may be reported when the patient has both.

  • A31 Infection due to other mycobacteria
    tuberculosis (A15-A19) names A15-A19, which includes this code

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 NVS020
Other nervous system disorders (neither hereditary nor degenerative)
Default principal diagnosis: inpatient No · outpatient No
CCSR INF001
Tuberculosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Tuberculosis

Tuberculosis (TB) is a bacterial disease that usually attacks the lungs. But it can also attack other parts of the body, including the kidneys, spine, and brain.

The full article covers:

  • What is tuberculosis (TB)?
  • What causes tuberculosis (TB)?
  • Who is more likely to get infected with tuberculosis (TB) germs?
  • Who is more likely to develop TB disease?
  • What are the symptoms of tuberculosis (TB)?
  • How is tuberculosis (TB) diagnosed?
  • What is the treatment for tuberculosis (TB)?

Read the full article at MedlinePlus

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

Convert A17.9 to ICD-9-CMHistory

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

ICD-9-CM
017.90 TB of organ NEC-unspec
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A17.9Overview

What is the ICD-10 code for tuberculosis of nervous system, unspecified?

The ICD-10-CM code for tuberculosis of nervous system, unspecified is A17.9 (sometimes written as A179). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A17.9 (Tuberculosis of nervous system) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report tuberculosis of nervous system, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A17.9 group to?

When tuberculosis of nervous system, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 975, 867, 869, 868, with relative weights from 0.6784 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A17.9 a CC or MCC?

CMS lists A17.9 as a CC (complication or comorbidity) for FY 2027. 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 14 closely related codes in its exclusion list.

Can A17.9 be reported with P37.0?

Not as a rule. The Excludes1 note at block A15-A19, which applies to A17.9, lists "congenital tuberculosis (P37.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).