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ICD-10-CM 2027 diagnosis code

K12.1Other forms of stomatitis

✓ Billable / specific

K12.1 is a valid, billable ICD-10-CM code for other forms of stomatitis. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Stomatitis, ICD-10 code for Vesicular stomatitis.

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 K12.1

K12.1 is the ICD-10-CM diagnosis code for other forms of stomatitis. It belongs to category K12 (stomatitis and related lesions), 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 K12, choose K12.1 (Other forms of stomatitis) only when documentation doesn't support a more specific option: recurrent oral aphthae (K12.0), cellulitis and abscess of mouth (K12.2) and oral mucositis (ulcerative) (K12.3).

Don't report K12.1 together with the conditions in its Excludes1 note: acute necrotizing ulcerative stomatitis (A69.1) and Vincent's stomatitis (A69.1).

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 528.09 (other stomatitis and mucositis (ulcerative)).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Stomatitis NOS
  • Denture stomatitis
  • Ulcerative stomatitis
  • Vesicular stomatitis
Excludes1Not coded here — never report together with this code
  • acute necrotizing ulcerative stomatitis (A69.1)
  • Vincent's stomatitis (A69.1)

Notes that apply from higher levels

Instructions written at a parent level also apply to K12.1.

› From K12 Stomatitis and related lesions
Excludes1
  • cancrum oris (A69.0)
  • cheilitis (K13.0)
  • gangrenous stomatitis (A69.0)
  • herpesviral [herpes simplex] gingivostomatitis (B00.2)
  • noma (A69.0)
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

13 entries

Terms in the official ICD-10-CM index that lead to K12.1.

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 →
  • 528.09Other stomatitis and mucositis (ulcerative)approximate

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 K12.1

Is K12.1 billable?

Yes. K12.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can K12.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict K12.1 as a principal diagnosis.

Is K12.1 a CC or MCC?

No. K12.1 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does K12.1 group to?

K12.1 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 K12.1?

The CMS General Equivalence Mappings map K12.1 to ICD-9-CM 528.09.