2026 ICD-10-CM Diagnosis Code S63.123ASubluxation of interphalangeal joint of unspecified thumb, initial encounter

ICD-10-CM Codes›S00–T88›S60-S69›S63

ICD-10-CM S63.123A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S63.123A is a billable ICD-10-CM diagnosis code for subluxation of interphalangeal joint of unspecified thumb, 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 562 through 563, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, initial encounter.

Code Identity

ICD-10-CM Code
S63.123A
Billable Status
Yes — Valid for Submission
Code Describes
Subluxation of interphalangeal joint of unspecified thumb, initial encounter
Short Description
Subluxation of interphalangeal joint of thmb, init
Parent Code
S63.123
Subluxation of interphalangeal joint of unspecified thumb

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS60-S69Injuries to the wrist, hand and fingers
CategoryS63Dislocation and sprain of joints and ligaments at wrist and hand level
This CodeS63.123ASubluxation of interphalangeal joint of unspecified thumb, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Closed dislocation of interphalangeal joint of thumb
  • Closed fracture dislocation of digit of hand
  • Closed fracture dislocation of interphalangeal joint of thumb
  • Closed fracture subluxation digit
  • Closed fracture subluxation of interphalangeal joint of thumb
  • Closed traumatic subluxation of digit of hand
  • Closed traumatic subluxation, interphalangeal joint of thumb
  • Fracture dislocation of thumb
  • Fracture subluxation of thumb
  • Open fracture dislocation of digit of hand
  • Open fracture dislocation of interphalangeal joint of thumb
  • Open fracture subluxation digit
  • Open fracture subluxation of interphalangeal joint of thumb
  • Open traumatic dislocation, interphalangeal joint,thumb
  • Open traumatic subluxation digit
  • Open traumatic subluxation, interphalangeal joint thumb

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments at wrist and hand level (S63). 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 INJ007
Dislocations, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Dislocations

Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints.

Read the full article at MedlinePlus

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

Convert S63.123A to ICD-9-CMHistory

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

ICD-9-CM
834.02 Disl interphaln hand-cl
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 S63.123AOverview

Is S63.123A (Subluxation of interphalangeal joint of unspecified thumb) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report subluxation of interphalangeal joint of unspecified thumb, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S63.123A mean?

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

What MS-DRG does S63.123A group to?

When subluxation of interphalangeal joint of unspecified thumb, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 562, 563, 963, 964, 965, with relative weights from 0.8955 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S63.123A?

Under the General Equivalence Mappings, subluxation of interphalangeal joint of unspecified thumb, initial encounter converts to ICD-9-CM 834.02 (disl interphaln hand-cl). 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.