2021 ICD-10-CM Code S20.369A

Insect bite (nonvenomous) of unspecified front wall of thorax, initial encounter

Version 2021
Replaced Code
Billable Code
7th Character Code
Unspecified Code
Initial Code
MS-DRG Mapping

Valid for Submission

S20.369A is a billable diagnosis code used to specify a medical diagnosis of insect bite (nonvenomous) of unspecified front wall of thorax, initial encounter. The code S20.369A is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

The ICD-10-CM code S20.369A might also be used to specify conditions or terms like insect bite, nonvenomous, of chest wall, nonvenomous insect bite of chest wall with infection or nonvenomous insect bite of chest wall without infection.

S20.369A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like insect bite (nonvenomous) of unspecified front wall of thorax. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Unspecified diagnosis codes like S20.369A are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

ICD-10:S20.369A
Short Description:Insect bite (nonvenomous) of unsp front wall of thorax, init
Long Description:Insect bite (nonvenomous) of unspecified front wall of thorax, initial encounter

Code Classification

Replaced Code

This code was replaced in the 2021 ICD-10 code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2020. This code was replaced for the FY 2021 (October 1, 2020 - September 30, 2021).


  • S20.364A - Insect bite of middle front wall of thorax, init

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Convert S20.369A to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code S20.369A its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Insect Bites and Stings

Also called: Bug bites

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. Travelers outside the United States may be at risk for malaria and other infections.

To prevent insect bites and their complications


[Learn More in MedlinePlus]

Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)