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K04.02 ICD-10-CM Code: Irreversible pulpitis

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

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too, and is marked with where it comes from.

The tabular list publishes no instructional note for this code itself.

Where it sits Source: CMS/NCHS

Under:Chapter 11: Diseases of the Digestive SystemK00-K14 Diseases of oral cavity and salivary glandsK04 Diseases of pulp and periapical tissuesK04.0 Pulpitis

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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 v44, Appendix B.

  • MS-DRG 011 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITH MCC (MDC PRE)
  • MS-DRG 012 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITH CC (MDC PRE)
  • MS-DRG 013 — TRACHEOSTOMY FOR FACE, MOUTH AND NECK DIAGNOSES OR LARYNGECTOMY WITHOUT CC/MCC (MDC PRE)
  • MS-DRG 157 — DENTAL AND ORAL DISEASES WITH MCC (MDC 03)
  • MS-DRG 158 — DENTAL AND ORAL DISEASES WITH CC (MDC 03)
  • MS-DRG 159 — DENTAL AND ORAL DISEASES WITHOUT CC/MCC (MDC 03)

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 context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Irreversible pulpitis is a billable ICD-10-CM diagnosis code (K04.02).

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

Official Coding Guidelines

No excerpt in the ICD-10-CM Official Guidelines names this code specifically. Its chapter carries only this chapter-wide note:

Chapter 11: Diseases of the Digestive System (K00-K95)

Reserved for future guideline expansion

Verify Before Coding

  • CC as a secondary diagnosis (FY2027). 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-derived relationships — computed from published CMS and AHRQ datasets

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 229 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 6 MS-DRGs: DRG 011 (MDC PRE), DRG 012 (MDC PRE), DRG 013 (MDC PRE), DRG 157 (MDC 03), DRG 158 (MDC 03), DRG 159 (MDC 03).

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

Clinical classification (AHRQ CCSR):DIG002 — Disorders of teeth and gingiva (default); DEN001 — Any dental condition including traumatic injury; DEN002 — Nontraumatic dental conditions.

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.

K03.2 — Erosion of teeth, K03.3 — Pathological resorption of teeth, K03.4 — Hypercementosis, K03.5 — Ankylosis of teeth, K03.6 — Deposits [accretions] on teeth, K03.7 — Posteruptive color changes of dental hard tissues, K03.81 — Cracked tooth, K03.89 — Other specified diseases of hard tissues of teeth, K03.9 — Disease of hard tissues of teeth, unspecified, K04.01 — Reversible pulpitis, K04.1 — Necrosis of pulp, K04.2 — Pulp degeneration, K04.3 — Abnormal hard tissue formation in pulp, K04.4 — Acute apical periodontitis of pulpal origin, K04.5 — Chronic apical periodontitis, K04.6 — Periapical abscess with sinus, K04.7 — Periapical abscess without sinus, K04.8 — Radicular cyst, K04.90 — Unspecified diseases of pulp and periapical tissues, K04.99 — Other diseases of pulp and periapical tissues, +208 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Disorders of teeth and gingiva, Any dental condition including traumatic injury, Nontraumatic dental conditions).

K03.3 — Pathological resorption of teeth, K03.4 — Hypercementosis, K03.5 — Ankylosis of teeth, K03.6 — Deposits [accretions] on teeth, K03.7 — Posteruptive color changes of dental hard tissues, K03.81 — Cracked tooth, K03.89 — Other specified diseases of hard tissues of teeth, K03.9 — Disease of hard tissues of teeth, unspecified, K04.0 — Pulpitis, K04.01 — Reversible pulpitis, K04.1 — Necrosis of pulp, K04.2 — Pulp degeneration, K04.3 — Abnormal hard tissue formation in pulp, K04.4 — Acute apical periodontitis of pulpal origin, K04.5 — Chronic apical periodontitis, K04.6 — Periapical abscess with sinus, K04.7 — Periapical abscess without sinus, K04.8 — Radicular cyst, K04.90 — Unspecified diseases of pulp and periapical tissues, K04.99 — Other diseases of pulp and periapical tissues, +613 more

Same Index main term, other category

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

J39.0 — Retropharyngeal and parapharyngeal abscess (parapharyngeal), J39.1 — Other abscess of pharynx (throat), J39.2 — Other diseases of pharynx (pharynx), J39.8 — Other specified diseases of upper respiratory tract (trachea), J85.1 — Abscess of lung with pneumonia (lung, with pneumonia), J85.2 — Abscess of lung without pneumonia (lung), J85.3 — Abscess of mediastinum (mediastinum), J86.0 — Pyothorax with fistula (chest, with fistula), J86.9 — Pyothorax without fistula (chest), J98.09 — Other diseases of bronchus, not elsewhere classified (bronchi), K05.20 — Aggressive periodontitis, unspecified (gum, aggressive), K05.211 — Aggressive periodontitis, localized, slight (gum, aggressive, localized, slight), K05.212 — Aggressive periodontitis, localized, moderate (gum, aggressive, localized, moderate), K05.213 — Aggressive periodontitis, localized, severe (gum, aggressive, localized, severe), K05.219 — Aggressive periodontitis, localized, unspecified severity (gum, aggressive, localized), K05.221 — Aggressive periodontitis, generalized, slight (gum, aggressive, generalized, slight), K05.222 — Aggressive periodontitis, generalized, moderate (gum, aggressive, generalized, moderate), K05.223 — Aggressive periodontitis, generalized, severe (gum, aggressive, generalized, severe), K05.229 — Aggressive periodontitis, generalized, unspecified severity (gum, aggressive, generalized), K06.8 — Other specified disorders of gingiva and edentulous alveolar ridge (gingiva, gum), +195 more

Contextual Map

Every relationship of K04.02 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.

Hierarchy

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • Pre-MDC[MDC crossing]: “Pre-MDC — 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. 175 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
  • MDC 03 — Diseases and Disorders of the Ear, Nose, Mouth and Throat[MDC crossing]: “Diseases and Disorders of the Ear, Nose, Mouth and Throat — 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. 5,151 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), pulp, pulpal (dental), irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Endodontitis, irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Infection, infected, infective (opportunistic), tooth, teeth, pulp, irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Odontomyelitis (closed) (open), irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Polyp, polypus, dental, irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Polyp, polypus, pulpal (dental), irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Pulpitis (acute) (anachoretic) (chronic) (hyperplastic) (putrescent) (suppurative) (ulcerative), irreversible[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (14)

Change history

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

Indexed Clinical Terms (7)

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.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "K04.02 — Irreversible pulpitis." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/k04.02-irreversible-pulpitis

Change history

  • FY2017 — October 1, 2016
    Added to the code set
    Irreversible pulpitis
    FY2017 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to K04.02 in its code family, with their registry titles.

View all codes in the K04 family