2026 ICD-10-CM Diagnosis Code S43.421DSprain of right rotator cuff capsule, subsequent encounter

ICD-10-CM Codes›S00–T88›S40-S49›S43

ICD-10-CM S43.421D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S43.421D is a billable ICD-10-CM diagnosis code for sprain of right rotator cuff capsule, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. Coders also document this condition as disorder of ligament of right shoulder joint. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, subsequent encounter.

This medical diagnosis code is frequently used in Orthopedics medical specialties to designate conditions such selected sprains rotator cuff, cruciate ligament, and ankle.

Code Identity

ICD-10-CM Code
S43.421D
Billable Status
Yes — Valid for Submission
Code Describes
Sprain of right rotator cuff capsule, subsequent encounter
Short Description
Sprain of right rotator cuff capsule, subsequent encounter
Same as the full description in the CMS dataset.
Parent Code
S43.421
Sprain of right rotator cuff capsule

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 CodeS43.421DSprain of right rotator cuff capsule, subsequent encounter

Present on Admission (POA)Billing

S43.421D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of ligament of right shoulder joint
  • Disorder of ligament of right shoulder region
  • Sprain of ligament of right shoulder joint
  • Sprain of right rotator cuff capsule
  • Sprain of shoulder

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 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ061
Sprains and strains, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Rotator Cuff Injuries

Your rotator cuff is part of your shoulder joint. It's a group of muscles and tendons that holds the top part of your upper arm bone firmly in your shoulder socket. The rotator cuff keeps your shoulder stable when you move your arm in any direction.

The full article covers:

  • What is a rotator cuff?
  • What are rotator cuff injuries?
  • Who is more likely to develop a rotator cuff injury?
  • What are the symptoms of rotator cuff injuries?
  • How are rotator cuff injuries diagnosed?
  • What are the treatments for rotator cuff injuries?
  • When should I see a health care provider for shoulder pain?

Read the full article at MedlinePlus

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

Convert S43.421D to ICD-9-CMHistory

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

ICD-9-CM
V58.89 Other specfied aftercare
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S43.421DOverview

Is S43.421D (Sprain of right rotator cuff capsule) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sprain of right rotator cuff capsule, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S43.421D mean?

The final character D marks a subsequent encounter: use it for routine care while the sprain of right rotator cuff capsule is healing, after active treatment has ended.

What MS-DRG does S43.421D group to?

When sprain of right rotator cuff capsule, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S43.421D exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for sprain of right rotator cuff capsule, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S43.421D?

Under the General Equivalence Mappings, sprain of right rotator cuff capsule, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.