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ICD-10-CM 2027 diagnosis code

S01.421ALaceration with foreign body of right cheek and temporomandibular area, initial encounter

✓ Billable / specificRequires 7th character

S01.421A is a valid, billable ICD-10-CM code for laceration with foreign body of right cheek and temporomandibular area, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Laceration w foreign body of right cheek and TMJ area, init

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 S01.421A

S01.421A is the ICD-10-CM diagnosis code for laceration with foreign body of right cheek and temporomandibular area, initial encounter. It belongs to category S01 (open wound of head), block S00-S09 (injuries to the head) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

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 604 (Trauma to the Skin, Subcutaneous Tissue and Breast with MCC, relative weight 1.453), DRG 605 (Trauma to the Skin, Subcutaneous Tissue and Breast without MCC, relative weight 0.9079), DRG 963 (Other Multiple Significant Trauma with MCC, relative weight 2.6363) and 2 more, in Pre-MDC, MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast) and MDC 24 (Multiple Significant Trauma), 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 873.51 (open wound of cheek, complicated) and 873.54 (open wound of jaw, complicated).

7th character

Ainitial encounter

Other encounter types for S01.421:

Notes that apply from higher levels

Instructions written at a parent level also apply to S01.421A.

› From S01 Open wound of head
Excludes1
  • open skull fracture (S02.- with 7th character B)
Excludes2
  • injury of eye and orbit (S05.-)
  • traumatic amputation of part of head (S08.-)
Code also
  • any associated:
  • injury of cranial nerve (S04.-)
  • injury of muscle and tendon of head (S09.1-)
  • intracranial injury (S06.-)
  • wound infection

Broader instructions also apply from S00-S09 Injuries to the head and Chapter 19: Injury, poisoning and certain other consequences of external causes.

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 →
  • 873.51Open wound of cheek, complicatedapproximate
  • 873.54Open wound of jaw, complicatedapproximate

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 S01.421A

Is S01.421A billable?

Yes. S01.421A is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "A" at the end of S01.421A mean?

It is the 7th character for initial encounter. Per the official guidelines, use it while the patient is receiving active treatment for the condition.

Can S01.421A be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict S01.421A as a principal diagnosis.

Is S01.421A a CC or MCC?

No. S01.421A is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does S01.421A group to?

S01.421A 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 604 (Trauma to the Skin, Subcutaneous Tissue and Breast with MCC), MS-DRG 605 (Trauma to the Skin, Subcutaneous Tissue and Breast without MCC), MS-DRG 963 (Other Multiple Significant Trauma with MCC) and 2 more. 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 S01.421A?

The CMS General Equivalence Mappings map S01.421A to ICD-9-CM 873.51 and 873.54.