2026 ICD-10-CM Diagnosis Code K05.5Other periodontal diseases

ICD-10-CM CodesK00–K95K00-K14K05

ICD-10-CM K05.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K05.5 is a billable ICD-10-CM diagnosis code for other periodontal diseases. 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. 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
K05.5
Billable Status
Yes — Valid for Submission
Code Describes
Other periodontal diseases
Short Description
Other periodontal diseases
Same as the full description in the CMS dataset.
Parent Code
Gingivitis and periodontal diseases

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK00-K14Diseases of oral cavity and salivary glands
CategoryK05Gingivitis and periodontal diseases
This CodeK05.5Other periodontal diseases

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Alveolar bone loss
  • Developmental anomaly of periodontal tissue
  • Gingival pocket
  • Injury of periodontal tissue
  • Intrabony periodontal defect
  • Necrotizing periodontal disease
  • Necrotizing ulcerative periodontitis
  • Periodontal and endodontic lesion
  • Periodontal ligament strain
  • Periodontal pocket
  • Primary endodontic lesion with secondary periodontal lesion
  • Primary periodontal lesion with secondary endodontic lesion
  • Thickened dental follicle
  • True combined periodontal and endodontic lesion
  • Vertical alveolar bone loss
  • Widened periodontal ligament space

Tabular List NotesGuidance

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

Inclusion Terms

  • Combined periodontic-endodontic lesion
  • Narrow gingival width (of periodontal soft tissue)

Type 2 Excludes

  • leukoplakia of gingiva K13.21

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

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

    • Disease, diseased
      • periodontal
        • specified NEC
    • Lesion(s) (nontraumatic)
      • combined periodontic - endodontic
    • Lesion(s) (nontraumatic)
      • periodontal, due to traumatic occlusion
    • Narrow
      • gingival width (of periodontal soft tissue)
    • Occlusion, occluded
      • traumatic
        • periodontal

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

Clinical InformationClinical

  • Periodontal Diseases

    pathological processes involving the periodontium including the gum (gingiva), the alveolar bone (alveolar process), the dental cementum, and the periodontal ligament.
  • Gingival Pocket

    an abnormal extension of a gingival sulcus not accompanied by the apical migration of the epithelial attachment.
  • Periodontal Debridement

    removal or disruption of dental deposits and plaque-retentive dental calculus from tooth surfaces and within the periodontal pocket space without deliberate removal of cementum as done in root planing and often in dental scaling. the goal is to conserve dental cementum to help maintain or re-establish healthy periodontal environment and eliminate periodontitis by using light instrumentation strokes and nonsurgical techniques (e.g., ultrasonic, laser instruments).
  • Periodontal Pocket

    an abnormal extension of a gingival sulcus accompanied by the apical migration of the epithelial attachment and bone resorption.
  • Alveolar Bone Loss

    resorption or wasting of the tooth-supporting bone (alveolar process) in the maxilla or mandible.
  • Gingival Pocket

    an abnormal deepening of a gingival sulcus not associated with destruction of the supporting periodontal tissue.

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 K05.5 to ICD-9-CMHistory

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

ICD-9-CM
523.8 Periodontal disease NEC
Approximate The match is approximate rather than exact.

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 K05.5Overview

Is K05.5 (Gingivitis and periodontal diseases) a billable code?

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

What MS-DRG does K05.5 group to?

When other periodontal diseases 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 K05.5?

Under the General Equivalence Mappings, other periodontal diseases converts to ICD-9-CM 523.8 (periodontal disease NEC). The mapping is approximate, so confirm the match fits the documentation.

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.