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A18.52 ICD-10-CM Code: Tuberculous keratitis

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 inclusion terms · 7 Excludes1 · 1 Excludes2 · 1 use-additional code

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 124 — OTHER DISORDERS OF THE EYE WITH MCC OR THROMBOLYTIC AGENT (MDC 02)
  • MS-DRG 125 — OTHER DISORDERS OF THE EYE WITHOUT MCC (MDC 02)
  • MS-DRG 974 — HIV WITH MAJOR RELATED CONDITION WITH MCC (MDC 25)
  • MS-DRG 975 — HIV WITH MAJOR RELATED CONDITION WITH CC (MDC 25)
  • MS-DRG 976 — HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC (MDC 25)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A18.52 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on A18.52 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • infections due to Mycobacterium tuberculosis and Mycobacterium bovis

Source: inherited from A15-A19

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Tuberculous interstitial keratitis
  • Tuberculous keratoconjunctivitis (interstitial) (phlyctenular)

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from A15-A19

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from A18.5

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code, if applicable, for associated cachexia (E88.A)

Source: inherited from A15-A19

Coder workflow for A18.52

MedCoder structured workflow — derived from this code’s own official record

Before you code A18.52

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with A18.52. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in A18.52’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewP37.0, R76.1, A15, J65, R76.11, B90

Consider A18.52. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes1 — check before selecting A18.52(7 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with A18.52: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareP37.0, R76.1, A15, J65, R76.11, B90

    See the official tabular notes · Guidelines I.A.12.a

  • Excludes2 — not part of A18.52(1 note)

    Coding workflow: The conditions named in this note are not included in A18.52. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareA18.4

    See the official tabular notes · Guidelines I.A.12.b

  • Use Additional Code — after identifying A18.52(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with A18.52 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewE88.A

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition A18.52 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewP37.0, R76.1, A15, J65, R76.11, B90

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with A18.52?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewE88.A

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Tuberculous keratitis is a billable ICD-10-CM diagnosis code (A18.52).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (12)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. 1 Use Additional Code instruction — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
  2. 7 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
  3. 1 Excludes2 entry — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name A18.52 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: A31 — Infection due to other mycobacteria (via A18.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 20 clinically related codes on its CMS exclusion list. Does not count toward severity when the stay groups to DRGs 974-976 (HIV with Major Related Condition).

Named in the grouper logic of 5 MS-DRGs: DRG 124 (MDC 02), DRG 125 (MDC 02), DRG 974 (MDC 25), DRG 975 (MDC 25), DRG 976 (MDC 25).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INF001 — Tuberculosis (default); EYE001 — Cornea and external disease.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

A17.9 — Tuberculosis of nervous system, unspecified, A18.50 — Tuberculosis of eye, unspecified, A18.51 — Tuberculous episcleritis, A18.53 — Tuberculous chorioretinitis, A18.54 — Tuberculous iridocyclitis, A18.59 — Other tuberculosis of eye, A18.82 — Tuberculosis of other endocrine glands, A18.84 — Tuberculosis of heart, A18.89 — Tuberculosis of other sites, A31.2 — Disseminated mycobacterium avium-intracellulare complex (DMAC), A31.8 — Other mycobacterial infections, A31.9 — Mycobacterial infection, unspecified, A49.3 — Mycoplasma infection, unspecified site, A49.8 — Other bacterial infections of unspecified site, A49.9 — Bacterial infection, unspecified, B92 — Sequelae of leprosy, B94.2 — Sequelae of viral hepatitis, B94.8 — Sequelae of other specified infectious and parasitic diseases, B94.9 — Sequelae of unspecified infectious and parasitic disease

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Tuberculosis, Cornea and external disease).

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, A18.31 — Tuberculous peritonitis, A18.32 — Tuberculous enteritis, A18.39 — Retroperitoneal tuberculosis, A18.4 — Tuberculosis of skin and subcutaneous tissue, A18.50 — Tuberculosis of eye, unspecified, A18.51 — Tuberculous episcleritis, 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, A18.81 — 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, +846 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Tuberculosis, tubercular, tuberculous”, “Keratitis”; these codes share that main term but sit in a different category of the Tabular List.

A15.6 — Tuberculous pleurisy (empyema), A15.7 — Primary respiratory tuberculosis (primary), A15.8 — Other respiratory tuberculosis (nose), A15.9 — Respiratory tuberculosis unspecified, A17.0 — Tuberculous meningitis (dura), A17.81 — Tuberculoma of brain and spinal cord (brain), A17.82 — Tuberculous meningoencephalitis (myelitis), A17.83 — Tuberculous neuritis (nerve), A17.89 — Other tuberculosis of nervous system (polyneuropathy), A17.9 — Tuberculosis of nervous system, unspecified (nervous system), A19.0 — Acute miliary tuberculosis of a single specified site (miliary, acute, single specified site), A19.1 — Acute miliary tuberculosis of multiple sites (multiple, acute), A19.2 — Acute miliary tuberculosis, unspecified (miliary, acute), A19.8 — Other miliary tuberculosis (miliary, chronic), A19.9 — Miliary tuberculosis, unspecified (miliary), A30.9 — Leprosy, unspecified (punctata, leprosa), A50.31 — Late congenital syphilitic interstitial keratitis (syphilitic), A54.33 — Gonococcal keratitis (gonococcal), A71.1 — Active stage of trachoma (trachomatous), B00.52 — Herpesviral keratitis (disciform), +36 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

HIV Screening Test

Contextual Map

Every relationship of A18.52 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run A18.52 with this related code in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 02 — Diseases and Disorders of the Eye[MDC crossing]: “Diseases and Disorders of the Eye — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1,200 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026
  • MDC 25 — Human Immunodeficiency Virus Infections[MDC crossing]: “Human Immunodeficiency Virus Infections — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026

Index entries (12)

  • Keratitis (nodular) (nonulcerative) (simple) (zonular), in (due to), tuberculosis[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Keratitis (nodular) (nonulcerative) (simple) (zonular), interstitial (nonsyphilitic), tuberculous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Keratitis (nodular) (nonulcerative) (simple) (zonular), tuberculous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Keratoconjunctivitis, tuberculous (phlyctenular)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Keratoscleritis, tuberculous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Phlyctenulosis (allergic) (keratoconjunctivitis) (nontuberculous), tuberculous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Sclerokeratitis, tuberculous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Tuberculosis, tubercular, tuberculous (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative), cornea (ulcer)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • and 4 more

Nearest codes (37)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "A18.52 — Tuberculous keratitis." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/a18.52-tuberculous-keratitis

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Tuberculous keratitis

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to A18.52 in its code family, with their registry titles.

View all codes in the A18 family