S43.203A — Unspecified subluxation of unspecified sternoclavicular joint, initial encounter
Is S43.203A billable?
Yes, but S43.203A will trip a Medicare edit. S43.203A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S43.203A under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
S43.203A at a glance
| Code | S43.203A |
|---|---|
| Description | Unspecified subluxation of unspecified sternoclavicular joint, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in S43.203A?
In S43.203A, the 7th character A means initial encounter. The 7th character is required for S43.203A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to S43.203A?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S43.203A directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does S43.203A group to?
S43.203A sits in MDC 04 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 183Major Chest Trauma with MCCmedical
- 184Major Chest Trauma with CCmedical
- 185Major Chest Trauma without CC/MCCmedical
As a secondary diagnosis, S43.203A is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG. It also carries Hospital-Acquired Condition category 05.
How is S43.203A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S43.20, the nearest indexed parent of S43.203A. Use them to find the family, then select the specific code.
- Subluxation › sternoclavicular
Use additional code — inherited from Chapter 19
Report an additional code alongside S43.203A to fully describe the condition. S43.203A is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S43.203A, but a patient may have both at the same time. When documentation supports it, S43.203A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S40-S49
The conditions below are not part of S43.203A, but a patient may have both at the same time. When documentation supports it, S43.203A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S43
The conditions below are not part of S43.203A, but a patient may have both at the same time. When documentation supports it, S43.203A and the excluded code may both be reported.
- strain of muscle, fascia and tendon of shoulder and upper arm (S46.-)
Code also — inherited from S43
Two codes may be needed to describe the condition fully. Whether S43.203A is sequenced first depends on the reason for the encounter.
- any associated open wound
How long has S43.203A existed?
S43.203A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.