2026 ICD-10-CM Diagnosis Code S64.31XDInjury of digital nerve of right thumb, subsequent encounter
S64.31XD is a billable ICD-10-CM diagnosis code for injury of digital nerve of right thumb, 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 injury of digital nerve of thumb. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to nerves, muscles and tendons, subsequent encounter.
Code Identity
Code Classification
Present on Admission (POA)Billing
S64.31XD 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 digital nerve of thumb
- Right thumb digital nerve traumatic injury
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of nerves at wrist and hand level (S64). 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.
Patient EducationClinical
Finger Injuries and Disorders
You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong with them, it can make life difficult. Common problems include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S64.31XD to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S64.31XDOverview
Is S64.31XD (Injury of digital nerve of right thumb) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report injury of digital nerve of right thumb, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character D in S64.31XD mean?
The final character D marks a subsequent encounter: use it for routine care while the injury of digital nerve of right thumb is healing, after active treatment has ended.
What MS-DRG does S64.31XD group to?
When injury of digital nerve of right thumb, 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 S64.31XD 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 injury of digital nerve of right thumb, subsequent encounter on inpatient claims.
What is the ICD-9 equivalent of S64.31XD?
Under the General Equivalence Mappings, injury of digital nerve of right thumb, 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.
