2026 ICD-10-CM Diagnosis Code S46.312SStrain of muscle, fascia and tendon of triceps, left arm, sequela

ICD-10-CM Codes›S00–T88›S40-S49›S46

ICD-10-CM S46.312S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S46.312S is a billable ICD-10-CM diagnosis code for strain of muscle, fascia and tendon of triceps, left arm, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 562 through 563. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.

Code Identity

ICD-10-CM Code
S46.312S
Billable Status
Yes — Valid for Submission
Code Describes
Strain of muscle, fascia and tendon of triceps, left arm, sequela
Short Description
Strain of musc/fasc/tend triceps, left arm, sequela
Parent Code
S46.312
Strain of muscle, fascia and tendon of triceps, left arm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS40-S49Injuries to the shoulder and upper arm
CategoryS46Injury of muscle, fascia and tendon at shoulder and upper arm level
This CodeS46.312SStrain of muscle, fascia and tendon of triceps, left arm, sequela

Present on Admission (POA)Billing

S46.312S 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.

  • Injury of muscle of left upper arm
  • Injury of triceps brachii muscle
  • Left triceps injury
  • Left triceps tendon tear
  • Rupture triceps tendon
  • Strain of left triceps brachii muscle
  • Strain of left triceps brachii muscle and/or tendon
  • Strain of muscle of left upper arm
  • Strain of muscle of upper arm
  • Strain of triceps brachii muscle
  • Strain of triceps brachii muscle and/or tendon

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at shoulder and upper arm level (S46). 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 INJ073
Injury, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Read the full article at MedlinePlus

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

Convert S46.312S to ICD-9-CMHistory

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

ICD-9-CM
905.7 Late effec sprain/strain
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 S46.312SOverview

Is S46.312S (Strain of muscle, fascia and tendon of triceps, left arm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report strain of muscle, fascia and tendon of triceps, left arm, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in S46.312S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the strain of muscle, fascia and tendon of triceps, left arm itself has resolved, not the original event.

What MS-DRG does S46.312S group to?

When strain of muscle, fascia and tendon of triceps, left arm, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, with relative weights from 0.8955 to 1.4248 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S46.312S 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 strain of muscle, fascia and tendon of triceps, left arm, sequela on inpatient claims.

What is the ICD-9 equivalent of S46.312S?

Under the General Equivalence Mappings, strain of muscle, fascia and tendon of triceps, left arm, sequela converts to ICD-9-CM 905.7 (late effec sprain/strain). 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.