A21.2 ICD-10-CM Code: Pulmonary tularemia

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A21.2 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 A21.2 itself; “inherited from” names the category or block whose note applies here.

Indexed Clinical Terms (6)

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.

• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), in (due to), tularemia
• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), tularemic
• Tularemia, bronchopneumonic
• Tularemia, pneumonia, pneumonic (any)
• Tularemia, pulmonary
• Tularemia, with, pneumonia

Don’t confuse A21.2 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of A21.2 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• A21.9— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Tularemia, unspecified” takes A21.9; specificity in the record moves it back here.

  Full comparison: A21.2 vs A21.9 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

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 A21.2 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 Excludes1 note: J17 — Pneumonia in diseases classified elsewhere.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

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 84 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 3 MS-DRGs: DRG 177 (MDC 04), DRG 178 (MDC 04), DRG 179 (MDC 04).

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

Clinical classification (AHRQ CCSR):RSP002 — Pneumonia (except that caused by tuberculosis) (default); INF003 — Bacterial infections.

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.

A22.1 — Pulmonary anthrax, A37.01 — Whooping cough due to Bordetella pertussis with pneumonia, A37.11 — Whooping cough due to Bordetella parapertussis with pneumonia, A37.81 — Whooping cough due to other Bordetella species with pneumonia, A37.91 — Whooping cough, unspecified species with pneumonia, A48.1 — Legionnaires' disease, B25.0 — Cytomegaloviral pneumonitis, B44.0 — Invasive pulmonary aspergillosis, J09.X1 — Influenza due to identified novel influenza A virus with pneumonia, J09.X2 — Influenza due to identified novel influenza A virus with other respiratory manifestations, J10.00 — Influenza due to other identified influenza virus with unspecified type of pneumonia, J10.01 — Influenza due to other identified influenza virus with the same other identified influenza virus pneumonia, J10.08 — Influenza due to other identified influenza virus with other specified pneumonia, J10.1 — Influenza due to other identified influenza virus with other respiratory manifestations, J11.00 — Influenza due to unidentified influenza virus with unspecified type of pneumonia, J11.08 — Influenza due to unidentified influenza virus with specified pneumonia, J11.1 — Influenza due to unidentified influenza virus with other respiratory manifestations, J15.29 — Pneumonia due to other staphylococcus, J15.5 — Pneumonia due to Escherichia coli, J15.61 — Pneumonia due to Acinetobacter baumannii, +63 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Pneumonia (except that caused by tuberculosis), Bacterial infections).

A01.03 — Typhoid pneumonia, A02.22 — Salmonella pneumonia, A20.2 — Pneumonic plague, A22.1 — Pulmonary anthrax, A31.0 — Pulmonary mycobacterial infection, A37.01 — Whooping cough due to Bordetella pertussis with pneumonia, A37.11 — Whooping cough due to Bordetella parapertussis with pneumonia, A37.81 — Whooping cough due to other Bordetella species with pneumonia, A37.91 — Whooping cough, unspecified species with pneumonia, A43.0 — Pulmonary nocardiosis, A48.1 — Legionnaires' disease, A50.04 — Early congenital syphilitic pneumonia, A52.72 — Syphilis of lung and bronchus, A54.84 — Gonococcal pneumonia, B01.2 — Varicella pneumonia, B05.2 — Measles complicated by pneumonia, B06.81 — Rubella pneumonia, B25.0 — Cytomegaloviral pneumonitis, B37.1 — Pulmonary candidiasis, B38.0 — Acute pulmonary coccidioidomycosis, +418 more

Same Index main term, other category

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

A01.03 — Typhoid pneumonia (in, typhoid), A02.22 — Salmonella pneumonia (Salmonella), A20.2 — Pneumonic plague (in, Yersinia pestis), A22.1 — Pulmonary anthrax (anthrax), A24.1 — Acute and fulminating melioidosis (in, Pseudomonas NEC, pseudomallei), A37.01 — Whooping cough due to Bordetella pertussis with pneumonia (in, whooping cough, due to, Bordetella pertussis), A37.11 — Whooping cough due to Bordetella parapertussis with pneumonia (in, whooping cough, due to, Bordetella parapertussis), A37.81 — Whooping cough due to other Bordetella species with pneumonia (in, whooping cough, due to, specified NEC), A37.91 — Whooping cough, unspecified species with pneumonia (in, whooping cough), A42.0 — Pulmonary actinomycosis (in, actinomycosis), A43.0 — Pulmonary nocardiosis (in, nocardiosis, nocardiasis), A50.04 — Early congenital syphilitic pneumonia (alba), A54.84 — Gonococcal pneumonia (gonococcal), A69.8 — Other specified spirochetal infections (spirochetal NEC), A70 — Chlamydia psittaci infections (psittacosis), A78 — Q fever (in, Q fever), B01.2 — Varicella pneumonia (varicella), B05.2 — Measles complicated by pneumonia (giant cell), B06.81 — Rubella pneumonia (in, rubella), B25.0 — Cytomegaloviral pneumonitis (cytomegaloviral), +82 more

Contextual Map

Every relationship of A21.2 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 A21.2 with this related code in Claim Check

Hierarchy

• A00-B99 — Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99) (A00-B99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A20-A28 — Certain zoonotic bacterial diseases[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• J17 — Pneumonia in diseases classified elsewhere[Excludes1]: “tularemia pneumonia (A21.2)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• RSP002 — Pneumonia (except that caused by tuberculosis)[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• INF003 — Bacterial infections[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 177 — RESPIRATORY INFECTIONS AND INFLAMMATIONS WITH MCC[MS-DRG]: “RESPIRATORY INFECTIONS AND INFLAMMATIONS WITH MCC (MDC 04)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 178 — RESPIRATORY INFECTIONS AND INFLAMMATIONS WITH CC[MS-DRG]: “RESPIRATORY INFECTIONS AND INFLAMMATIONS WITH CC (MDC 04)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 179 — RESPIRATORY INFECTIONS AND INFLAMMATIONS WITHOUT CC/MCC[MS-DRG]: “RESPIRATORY INFECTIONS AND INFLAMMATIONS WITHOUT CC/MCC (MDC 04)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 04 — Diseases and Disorders of the Respiratory System[MDC crossing]: “Diseases and Disorders of the Respiratory System — 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. 3,998 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), in (due to), tularemia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved), tularemic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Tularemia, bronchopneumonic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Tularemia, pneumonia, pneumonic (any)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Tularemia, pulmonary[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Tularemia, with, pneumonia[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

• A21 — Tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.0 — Ulceroglandular tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.1 — Oculoglandular tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.3 — Gastrointestinal tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.7 — Generalized tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.8 — Other forms of tularemia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• A21.9 — Tularemia, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to A21.2 in its code family, with their registry titles.

• A21 — Tularemia
• A21.0 — Ulceroglandular tularemia
• A21.1 — Oculoglandular tularemia
• A21.3 — Gastrointestinal tularemia
• A21.7 — Generalized tularemia
• A21.8 — Other forms of tularemia
• A21.9 — Tularemia, unspecified

View all codes in the A21 family