2026 ICD-10-CM Diagnosis Code S61.059AOpen bite of unspecified thumb without damage to nail, initial encounter
S61.059A is a billable ICD-10-CM diagnosis code for open bite of unspecified thumb without damage to nail, 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 604 through 605, 963 through 965. Coders also document this condition as animal bite of thumb. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Animal bite of thumb
- Dog bite of thumb
- Human bite of hand
- Human bite of thumb
- Open bite of thumb
- Open wound of thumb due to cat bite
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Open wound of wrist, hand and fingers (S61). 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
Animal Bites
Wild animals usually avoid people. They might attack, however, if they feel threatened, are sick, or are protecting their young or territory. Attacks by pets are more common. Animal bites rarely are life-threatening, but if they become infected, you can develop serious medical problems.
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Convert S61.059A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S61.059AOverview
Is S61.059A (Open bite of unspecified thumb without damage to nail) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report open bite of unspecified thumb without damage to nail, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S61.059A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for open bite of unspecified thumb without damage to nail, such as an emergency visit or first evaluation.
What MS-DRG does S61.059A group to?
When open bite of unspecified thumb without damage to nail, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, 963, 964, 965, with relative weights from 0.9160 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S61.059A?
Under the General Equivalence Mappings, open bite of unspecified thumb without damage to nail, initial encounter converts to ICD-9-CM 883.0 (open wound of finger). 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.
