2026 ICD-10-CM Diagnosis Code S13.5XXASprain of thyroid region, initial encounter

ICD-10-CM Codes›S00–T88›S10-S19›S13

ICD-10-CM S13.5XXA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S13.5XXA is a billable ICD-10-CM diagnosis code for sprain of thyroid region, 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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566, 963 through 965. Coders also document this condition as complete tear, thyroid region ligament. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sprains and strains, initial encounter.

Code Identity

ICD-10-CM Code
S13.5XXA
Billable Status
Yes — Valid for Submission
Code Describes
Sprain of thyroid region, initial encounter
Short Description
Sprain of thyroid region, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S13.5
Sprain of thyroid region

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS10-S19Injuries to the neck
CategoryS13Dislocation and sprain of joints and ligaments at neck level
This CodeS13.5XXASprain of thyroid region, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Complete tear, thyroid region ligament
  • Neck sprain
  • Sprain of ligament of cricoarytenoid joint
  • Sprain of ligament of cricothyroid joint
  • Sprain of thyroid cartilage
  • Thyroid region sprain

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments at neck level (S13). 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 INJ024
Sprains and strains, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Neck Sprain

    stretching or tearing of ligaments in the neck.

Patient EducationClinical

Neck Injuries and Disorders

Any part of your neck - muscles, bones, joints, tendons, ligaments, or nerves - can cause neck problems. Neck pain is very common. Pain may also come from your shoulder, jaw, head, or upper arms.

Read the full article at MedlinePlus

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

Convert S13.5XXA to ICD-9-CMHistory

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

ICD-9-CM
848.2 Sprain of thyroid region
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 S13.5XXAOverview

Is S13.5XXA (Sprain of thyroid region) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sprain of thyroid region, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S13.5XXA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for sprain of thyroid region, such as an emergency visit or first evaluation.

What MS-DRG does S13.5XXA group to?

When sprain of thyroid region, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, 963, 964, 965, with relative weights from 0.7493 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S13.5XXA?

Under the General Equivalence Mappings, sprain of thyroid region, initial encounter converts to ICD-9-CM 848.2 (sprain of thyroid region). 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.