2026 ICD-10-CM Diagnosis Code S70.361AInsect bite (nonvenomous), right thigh, initial encounter

ICD-10-CM CodesS00–T88S70-S79S70

ICD-10-CM S70.361A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S70.361A is a billable ICD-10-CM diagnosis code for insect bite (nonvenomous), right thigh, 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 606 through 607, 963 through 965. Coders also document this condition as infected wound of right thigh due to nonvenomous insect bite. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, initial encounter.

Code Identity

ICD-10-CM Code
S70.361A
Billable Status
Yes — Valid for Submission
Code Describes
Insect bite (nonvenomous), right thigh, initial encounter
Short Description
Insect bite (nonvenomous), right thigh, initial encounter
Same as the full description in the CMS dataset.
Parent Code
Insect bite (nonvenomous), right thigh

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS70-S79Injuries to the hip and thigh
CategoryS70Superficial injury of hip and thigh
This CodeS70.361AInsect bite (nonvenomous), right thigh, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infected wound of right thigh due to nonvenomous insect bite
  • Insect bite, nonvenomous, of thigh
  • Nonvenomous insect bite of thigh with infection
  • Superficial injury of thigh with infection
  • Wound of right thigh due to nonvenomous insect bite

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of hip and thigh (S70). 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 INJ017
Superficial injury; contusion, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Insect Bites and Stings

Most insect bites are harmless, though they sometimes cause discomfort. Bee, wasp, and hornet stings and fire ant bites usually hurt. Mosquito and flea bites usually itch. Insects can also spread diseases. In the United States, some mosquitoes spread West Nile virus.

Read the full article at MedlinePlus

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

Convert S70.361A to ICD-9-CMHistory

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

ICD-9-CM
916.4 Insect bite hip & leg
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 S70.361AOverview

Is S70.361A (Insect bite (nonvenomous), right thigh) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report insect bite (nonvenomous), right thigh, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S70.361A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for insect bite (nonvenomous), right thigh, such as an emergency visit or first evaluation.

What MS-DRG does S70.361A group to?

When insect bite (nonvenomous), right thigh, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, 963, 964, 965, with relative weights from 0.9064 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of S70.361A?

Under the General Equivalence Mappings, insect bite (nonvenomous), right thigh, initial encounter converts to ICD-9-CM 916.4 (insect bite hip & leg). 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.