2027 ICD-10-CM Diagnosis Code S20.364DInsect bite (nonvenomous) of middle front wall of thorax, subsequent encounter

ICD-10-CM Codes›S00–T88›S20-S29›S20

ICD-10-CM S20.364D
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S20.364D is a billable ICD-10-CM diagnosis code for insect bite (nonvenomous) of middle front wall of thorax, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, subsequent encounter.

Code Identity

ICD-10-CM Code
S20.364D
Billable Status
Yes — Valid for Submission
Code Describes
Insect bite (nonvenomous) of middle front wall of thorax, subsequent encounter
Short Description
Insect bite of middle front wall of thorax, subs
Parent Code
S20.364
Insect bite (nonvenomous) of middle front wall of thorax

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS20Superficial injury of thorax
This CodeS20.364DInsect bite (nonvenomous) of middle front wall of thorax, subsequent encounter

Present on Admission (POA)Billing

S20.364D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the thorax (S20-S29).

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of thorax (S20). 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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S20.364D: its own notes plus those printed at S20, block S20-S29, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • injuries of breast
  • injuries of chest (wall)
  • injuries of interscapular area

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block S20-S29 Injuries to the thorax applies to 1,602 codes
  • burns and corrosions (T20-T32)
  • effects of foreign body in bronchus (T17.5)
  • effects of foreign body in esophagus (T18.1)
  • effects of foreign body in lung (T17.8)
  • effects of foreign body in trachea (T17.4)
  • frostbite (T33-T34)
  • injuries of axilla
  • injuries of clavicle
  • injuries of scapular region
  • injuries of shoulder
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S20 Superficial injury of thorax applies to 294 codes
  • The appropriate 7th character is to be added to each code from category S20
Values for category S20 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter this code
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ054
Superficial injury; contusion, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement S20.364D replaces the following previously assigned code(s):

  • S20.361D - Insect bite (nonvenomous) of r frnt wl of thorax, subs
  • S20.362D - Insect bite (nonvenomous) of left front wall of thorax, subs
  • S20.369D - Insect bite (nonvenomous) of unsp front wall of thorax, subs
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S20.364DOverview

Is S20.364D (Insect bite (nonvenomous) of middle front wall of thorax) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report insect bite (nonvenomous) of middle front wall of thorax, subsequent encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character D in S20.364D mean?

The final character D marks a subsequent encounter: use it for routine care while the insect bite (nonvenomous) of middle front wall of thorax is healing, after active treatment has ended.

What MS-DRG does S20.364D group to?

When insect bite (nonvenomous) of middle front wall of thorax, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 950, 949, with relative weights from 0.7661 to 1.1231 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S20.364D 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 insect bite (nonvenomous) of middle front wall of thorax, subsequent encounter on inpatient claims. The code appears in the Injuries to the thorax (S20-S29) range of the CMS exempt list.