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A33 ICD-10-CM Code: Tetanus neonatorum

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

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 794 — NEONATE WITH OTHER SIGNIFICANT PROBLEMS (MDC 15)

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.

Code Overview

Tetanus neonatorum is a billable ICD-10-CM diagnosis code (A33).

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 (4)

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.

Verify Before Coding

  • Age-restricted: the Medicare Code Editor lists this as a perinatal/newborn (age 0 only) diagnosis; other ages are presumed incorrect.
  • MCC 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 A33 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 2 Excludes1 notes across 2 chapters: A35 — Other tetanus, P38 — Omphalitis of newborn.

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

Referenced by 6 Excludes2 notes: P35 — Congenital viral diseases, P35-P39 — Infections specific to the perinatal period (P35-P39), P36 — Bacterial sepsis of newborn, P37 — Other congenital infectious and parasitic diseases, P38 — Omphalitis of newborn, P39 — Other infections specific to the perinatal period.

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: MCC — Major 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 18 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 1 MS-DRG: DRG 794 (MDC 15).

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

Clinical classification (AHRQ CCSR):PNL009 — Perinatal infections (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 MCC — 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.

P29.0 — Neonatal cardiac failure, P29.11 — Neonatal tachycardia, P29.12 — Neonatal bradycardia, P29.2 — Neonatal hypertension, P29.4 — Transient myocardial ischemia in newborn, P29.89 — Other cardiovascular disorders originating in the perinatal period, P29.9 — Cardiovascular disorder originating in the perinatal period, unspecified, P94.1 — Congenital hypertonia, P94.2 — Congenital hypotonia, P94.8 — Other disorders of muscle tone of newborn, P94.9 — Disorder of muscle tone of newborn, unspecified, P96.0 — Congenital renal failure, P96.3 — Wide cranial sutures of newborn, P96.5 — Complication to newborn due to (fetal) intrauterine procedure, P96.82 — Delayed separation of umbilical cord, P96.83 — Meconium staining, P96.89 — Other specified conditions originating in the perinatal period

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Perinatal infections, Bacterial infections).

A48.51 — Infant botulism, A50.01 — Early congenital syphilitic oculopathy, A50.02 — Early congenital syphilitic osteochondropathy, A50.03 — Early congenital syphilitic pharyngitis, A50.04 — Early congenital syphilitic pneumonia, A50.05 — Early congenital syphilitic rhinitis, A50.06 — Early cutaneous congenital syphilis, A50.07 — Early mucocutaneous congenital syphilis, A50.08 — Early visceral congenital syphilis, A50.09 — Other early congenital syphilis, symptomatic, A50.1 — Early congenital syphilis, latent, A50.2 — Early congenital syphilis, unspecified, A50.30 — Late congenital syphilitic oculopathy, unspecified, A50.31 — Late congenital syphilitic interstitial keratitis, A50.32 — Late congenital syphilitic chorioretinitis, A50.39 — Other late congenital syphilitic oculopathy, A50.40 — Late congenital neurosyphilis, unspecified, A50.41 — Late congenital syphilitic meningitis, A50.42 — Late congenital syphilitic encephalitis, A50.43 — Late congenital syphilitic polyneuropathy, +439 more

Same Index main term, other category

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

A34 — Obstetrical tetanus (obstetrical), A35 — Other tetanus, L08.82 — Omphalitis not of newborn (not of newborn), O08.0 — Genital tract and pelvic infection following ectopic and molar pregnancy (with, ectopic or molar pregnancy), P38.1 — Omphalitis with mild hemorrhage (with mild hemorrhage), P38.9 — Omphalitis without hemorrhage, R25.2 — Cramp and spasm

Contextual Map

Every relationship of A33 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 A33 with these 7 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • A35 — Other tetanus[Excludes1]: “tetanus neonatorum (A33)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • P38 — Omphalitis of newborn[Excludes1]: “tetanus omphalitis (A33)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

  • MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
  • DRG 794 — NEONATE WITH OTHER SIGNIFICANT PROBLEMS[MS-DRG]: “NEONATE WITH OTHER SIGNIFICANT PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

Index entries

  • Omphalitis (congenital) (newborn), tetanus[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Tetanus, tetanic (cephalic) (convulsions), neonatorum[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Trismus, neonatorum[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Trismus, newborn[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · 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

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. "A33 — Tetanus neonatorum." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/a33-tetanus-neonatorum

Change history

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

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.