2027 ICD-10-CM Diagnosis Code S53.421AUlnohumeral (joint) sprain of right elbow, initial encounter

ICD-10-CM Codes›S00–T88›S50-S59›S53

ICD-10-CM S53.421A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S53.421A is a billable ICD-10-CM diagnosis code for ulnohumeral (joint) sprain of right elbow, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 562 through 563, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.

Code Identity

ICD-10-CM Code
S53.421A
Billable Status
Yes — Valid for Submission
Code Describes
Ulnohumeral (joint) sprain of right elbow, initial encounter
Short Description
Ulnohumeral (joint) sprain of right elbow, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S53.421
Ulnohumeral (joint) sprain of right elbow

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS50-S59Injuries to the elbow and forearm
CategoryS53Dislocation and sprain of joints and ligaments of elbow
This CodeS53.421AUlnohumeral (joint) sprain of right elbow, initial encounter

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of elbow (S53). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S53.421A: its own notes plus those printed at S53.4, S53, block S50-S59, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From S53 Dislocation and sprain of joints and ligaments of elbow applies to 261 codes
  • avulsion of joint or ligament of elbow
  • laceration of cartilage, joint or ligament of elbow
  • sprain of cartilage, joint or ligament of elbow
  • traumatic hemarthrosis of joint or ligament of elbow
  • traumatic rupture of joint or ligament of elbow
  • traumatic subluxation of joint or ligament of elbow
  • traumatic tear of joint or ligament of elbow

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From S53.4 Sprain of elbow applies to 54 codes
  • traumatic rupture of radial collateral ligament (S53.2-)
  • traumatic rupture of ulnar collateral ligament (S53.3-)
From S53 Dislocation and sprain of joints and ligaments of elbow applies to 261 codes
  • strain of muscle, fascia and tendon at forearm level (S56.-)
From Block S50-S59 Injuries to the elbow and forearm applies to 4,362 codes
  • burns and corrosions (T20-T32)
  • frostbite (T33-T34)
  • injuries of wrist and hand (S60-S69)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S53 Dislocation and sprain of joints and ligaments of elbow applies to 261 codes
  • any associated open wound

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S53 Dislocation and sprain of joints and ligaments of elbow applies to 261 codes
  • The appropriate 7th character is to be added to each code from category S53
Values for category S53 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name S53.421A, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S53.421A: its condition is not part of those codes, and both may be reported when the patient has both.

  • S56 Injury of muscle, fascia and tendon at forearm level
    sprain of joints and ligaments of elbow (S53.4-) names S53.4-, which includes this code

Clinical ClassificationClinical

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

CCSR INJ024
Sprains and strains, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Elbow Injuries and Disorders

Your elbow joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the elbow joint move. When any of these structures is hurt or diseased, you have elbow problems.

Read the full article at MedlinePlus

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

Convert S53.421A to ICD-9-CMHistory

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

ICD-9-CM
841.3 Sprain ulnohumeral
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S53.421AOverview

What is the ICD-10 code for ulnohumeral (joint) sprain of right elbow, initial encounter?

The ICD-10-CM code for ulnohumeral (joint) sprain of right elbow, initial encounter is S53.421A (sometimes written as S53421A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is S53.421A (Ulnohumeral (joint) sprain of right elbow) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report ulnohumeral (joint) sprain of right elbow, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S53.421A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for ulnohumeral (joint) sprain of right elbow, such as an emergency visit or first evaluation.

What MS-DRG does S53.421A group to?

When ulnohumeral (joint) sprain of right elbow, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 563, 964, 965, 562, 963, with relative weights from 0.8982 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S53.421A?

Under the General Equivalence Mappings, ulnohumeral (joint) sprain of right elbow, initial encounter converts to ICD-9-CM 841.3 (sprain ulnohumeral). The mapping is approximate, so confirm the match fits the documentation.