2027 ICD-10-CM Diagnosis Code S43.223APosterior subluxation of unspecified sternoclavicular joint, initial encounter

ICD-10-CM Codes›S00–T88›S40-S49›S43

ICD-10-CM S43.223A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S43.223A is a billable ICD-10-CM diagnosis code for posterior subluxation of unspecified sternoclavicular joint, 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 183 through 185, 963 through 965. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 19 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, initial encounter.

Code Identity

ICD-10-CM Code
S43.223A
Billable Status
Yes — Valid for Submission
Code Describes
Posterior subluxation of unspecified sternoclavicular joint, initial encounter
Short Description
Posterior subluxation of unsp sternoclavicular joint, init
Parent Code
S43.223
Posterior subluxation of unspecified sternoclavicular joint

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS40-S49Injuries to the shoulder and upper arm
CategoryS43Dislocation and sprain of joints and ligaments of shoulder girdle
This CodeS43.223APosterior subluxation of unspecified sternoclavicular joint, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for S43.223A.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed fracture dislocation sternoclavicular joint, posterior
  • Closed fracture subluxation sternoclavicular joint, posterior
  • Closed traumatic dislocation, sternoclavicular joint, posterior
  • Closed traumatic subluxation of sternum
  • Closed traumatic subluxation sternoclavicular joint
  • Closed traumatic subluxation, sternoclavicular joint, posterior
  • Fracture dislocation of sternoclavicular joint
  • Fracture subluxation of sternoclavicular joint
  • Open fracture dislocation sternoclavicular joint, posterior
  • Open fracture subluxation sternoclavicular joint, posterior
  • Open traumatic dislocation sternoclavicular joint
  • Open traumatic dislocation, sternoclavicular joint, posterior
  • Open traumatic subluxation of sternum
  • Open traumatic subluxation sternoclavicular joint
  • Open traumatic subluxation, sternoclavicular joint, posterior
  • Posterior dislocation of sternoclavicular joint

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments of shoulder girdle (S43). 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 S43.223A: its own notes plus those printed at S43, block S40-S49, 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 S43 Dislocation and sprain of joints and ligaments of shoulder girdle applies to 333 codes
  • avulsion of joint or ligament of shoulder girdle
  • laceration of cartilage, joint or ligament of shoulder girdle
  • sprain of cartilage, joint or ligament of shoulder girdle
  • traumatic hemarthrosis of joint or ligament of shoulder girdle
  • traumatic rupture of joint or ligament of shoulder girdle
  • traumatic subluxation of joint or ligament of shoulder girdle
  • traumatic tear of joint or ligament of shoulder girdle
From Block S40-S49 Injuries to the shoulder and upper arm applies to 2,730 codes
  • injuries of axilla
  • injuries of scapular region

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 S43 Dislocation and sprain of joints and ligaments of shoulder girdle applies to 333 codes
  • strain of muscle, fascia and tendon of shoulder and upper arm (S46.-)
From Block S40-S49 Injuries to the shoulder and upper arm applies to 2,730 codes
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 S43 Dislocation and sprain of joints and ligaments of shoulder girdle applies to 333 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 S43 Dislocation and sprain of joints and ligaments of shoulder girdle applies to 333 codes
  • The appropriate 7th character is to be added to each code from category S43
Values for category S43 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 S43.223A, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming S43.223A: its condition is not part of those codes, and both may be reported when the patient has both.

  • S23 Dislocation and sprain of joints and ligaments of thorax
    dislocation, sprain of sternoclavicular joint (S43.2, S43.6) names S43.2, which includes this code

Clinical ClassificationClinical

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

CCSR INJ007
Dislocations, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Dislocated Shoulder

Your shoulder joint is made up of three bones: your collarbone, your shoulder blade, and your upper arm bone. The top of your upper arm bone is shaped like a ball. This ball fits into a cuplike socket in your shoulder blade. A shoulder dislocation is an injury that happens when the ball pops out of your socket.

The full article covers:

  • What is a dislocated shoulder?
  • What causes a dislocated shoulder?
  • Who is at risk for a dislocated shoulder?
  • What are the symptoms of a dislocated shoulder?
  • How is a dislocated shoulder diagnosed?
  • What are the treatments for a dislocated shoulder?

Read the full article at MedlinePlus

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

Convert S43.223A to ICD-9-CMHistory

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

ICD-9-CM
839.61 Dislocat sternum-closed
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 S43.223AOverview

Is S43.223A (Posterior subluxation of unspecified sternoclavicular joint) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report posterior subluxation of unspecified sternoclavicular joint, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S43.223A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for posterior subluxation of unspecified sternoclavicular joint, such as an emergency visit or first evaluation.

What MS-DRG does S43.223A group to?

When posterior subluxation of unspecified sternoclavicular joint, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 185, 183, 963, 184, with relative weights from 0.7712 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S43.223A a CC or MCC?

CMS lists S43.223A as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 19 closely related codes in its exclusion list.

What is the ICD-9 equivalent of S43.223A?

Under the General Equivalence Mappings, posterior subluxation of unspecified sternoclavicular joint, initial encounter converts to ICD-9-CM 839.61 (dislocat sternum-closed). The mapping is approximate, so confirm the match fits the documentation.