2026 ICD-10-CM Diagnosis Code K04.5Chronic apical periodontitis

ICD-10-CM Codes›K00–K95›K00-K14›K04

ICD-10-CM K04.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K04.5 is a billable ICD-10-CM diagnosis code for chronic apical periodontitis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 157 through 159. Coders also document this condition as apical granuloma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury; Caries, periodontitis, and other preventable dental conditions; and Disorders of teeth and gingiva.

Code Identity

ICD-10-CM Code
K04.5
Billable Status
Yes — Valid for Submission
Code Describes
Chronic apical periodontitis
Short Description
Chronic apical periodontitis
Same as the full description in the CMS dataset.
Parent Code
K04
Diseases of pulp and periapical tissues

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK00-K14Diseases of oral cavity and salivary glands
CategoryK04Diseases of pulp and periapical tissues
This CodeK04.5Chronic apical periodontitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Apical granuloma
  • Apical periodontitis
  • Asymptomatic periapical periodontitis
  • Dental peri-implantitis
  • Inflammatory lesion of periapical tissue surrounding dental implant
  • Phoenix abscess
  • Symptomatic periapical periodontitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Apical or periapical granuloma
  • Apical periodontitis NOS

Type 1 Excludes

  • chronic periodontitis K05.3

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Granuloma
      • apical
    • Granuloma
      • dental
    • Granuloma
      • periapical
    • Granuloma
      • pyogenic, pyogenicum (of) (skin)
        • maxillary alveolar ridge
    • Infection, infected, infective(opportunistic)
      • periapical
    • Periodontitis(chronic) (complex) (compound) (local) (simplex)
      • apical

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR DEN001
Any dental condition including traumatic injury
Default principal diagnosis: inpatient No · outpatient No
CCSR DEN003
Caries, periodontitis, and other preventable dental conditions
Default principal diagnosis: inpatient No · outpatient No
CCSR DIG002
Disorders of teeth and gingiva
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR DEN002
Nontraumatic dental conditions
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Gum Disease

If you have gum disease, you're not alone. Many U.S. adults currently have some form of the disease. It ranges from simple gum inflammation, called gingivitis, to serious damage to the tissue and bone supporting the teeth. In the worst cases, you can lose teeth.

Read the full article at MedlinePlus

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

Convert K04.5 to ICD-9-CMHistory

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

ICD-9-CM
522.6 Chr apical periodontitis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K04.5Overview

Is K04.5 (Diseases of pulp and periapical tissues) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic apical periodontitis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K04.5 group to?

When chronic apical periodontitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 157, 158, 159, with relative weights from 0.7085 to 1.7168 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K04.5?

Under the General Equivalence Mappings, chronic apical periodontitis converts to ICD-9-CM 522.6 (chr apical periodontitis). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.