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ICD-10-CM 2027 diagnosis code

K05.5Other periodontal diseases

✓ Billable / specific

K05.5 is a valid, billable ICD-10-CM code for other periodontal diseases. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About K05.5

K05.5 is the ICD-10-CM diagnosis code for other periodontal diseases. It belongs to category K05 (gingivitis and periodontal diseases), block K00-K14 (diseases of oral cavity and salivary glands) and chapter 11 (diseases of the digestive system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within K05, choose K05.5 (Other periodontal diseases) only when documentation doesn't support a more specific option: acute gingivitis (K05.0), chronic gingivitis (K05.1), aggressive periodontitis (K05.2), chronic periodontitis (K05.3), Periodontosis (K05.4) and periodontal disease, unspecified (K05.6).

The conditions in its Excludes2 note aren't part of K05.5, but may be coded alongside it if the patient has both: leukoplakia of gingiva (K13.21).

Use an additional code to identify: alcohol abuse and dependence (F10.-), exposure to environmental tobacco smoke (Z77.22), exposure to tobacco smoke in the perinatal period (P96.81), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31) and 2 more.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 157 (Dental and Oral Diseases with MCC, relative weight 1.809), DRG 158 (Dental and Oral Diseases with CC, relative weight 0.9366) and DRG 159 (Dental and Oral Diseases without CC/MCC, relative weight 0.6893), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 523.8 (other specified periodontal diseases).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Combined periodontic-endodontic lesion
  • Narrow gingival width (of periodontal soft tissue)
Excludes2Not included here — may be reported together if both conditions exist
  • leukoplakia of gingiva (K13.21)

Notes that apply from higher levels

Instructions written at a parent level also apply to K05.5.

› From K05 Gingivitis and periodontal diseases
Use additional code
  • code to identify:
  • alcohol abuse and dependence (F10.-)
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Broader instructions also apply from Chapter 11: Diseases of the digestive system.

Alphabetic index entries

5 entries

Terms in the official ICD-10-CM index that lead to K05.5.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 523.8Other specified periodontal diseasesapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about K05.5

Is K05.5 billable?

Yes. K05.5 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can K05.5 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict K05.5 as a principal diagnosis.

Is K05.5 a CC or MCC?

No. K05.5 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does K05.5 group to?

K05.5 is used in the MS-DRG v44.0 logic for MS-DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC), MS-DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC), MS-DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC), MS-DRG 157 (Dental and Oral Diseases with MCC), MS-DRG 158 (Dental and Oral Diseases with CC) and MS-DRG 159 (Dental and Oral Diseases without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for K05.5?

The CMS General Equivalence Mappings map K05.5 to ICD-9-CM 523.8.