Chapter 19: Injury and Poisoning, and Certain Other Consequences of External Causes (S00 – T88) – Part II

on Monday, 08 September 2014. All News Items | Coding

Part I can be found by clicking here.

Coding of Burns and Corrosions

There is now a distinction made in ICD-10-CM between burns and corrosions. Coding guidelines are the same for both burns and corrosions. The difference between the two would be:

  • Burns – Thermal burns from a heat source.
  1. Fire
  2. Hot appliance
  3. Electricity
  4. Radiation
  5. Sunburns are not included
  • Corrosion – A burn secondary to chemicals (as it makes contact with external or internal tissue) such as:
  1. Acids
  2. Bases
  3. Oxidizers
  4. Solvents
  5. Alkylants
  6. Mustard gas

Current burns are classified in ICD-10-CM by:

  • Body site
  • Depth – Burns located at the same site but of different degrees is coded to the highest degree documented by provider
    • First degree – erythema
    • Second degree – blistering
    • Third degree – full thickness injury
  • Extent – Total Body Surface (TBS) for Third Degree Burns
  1. Burns – Category T31
  2. Corrosions – Category T32
  • T31 and T32 are based on the classic “rule of nines” in estimating TBS
  1. Head and neck – 9%
  2. Each arm – 9%
  3. Each leg – 18%
  4. Anterior trunk – 18%
  5. Posterior trunk – 18%
  6. Genitalia – 1%
  • Percentage assignment may be changed by providers to accommodate patients with larger heads, buttocks, thighs or abdomen
  • Categories T30.0 and T30.4 for Burn or Corrosion of unspecified body region, unspecified degree are not to be assigned on inpatient accounts
  • External cause / Agent
  • Laterality
    • Left
    • Right
    • Unspecified
  • Encounter – Seventh character designates episode of care
    • Initial encounter – A
    • Subsequent encounter – D
    • Sequela – S (encounters for late effects of burns or corrosions such as scars or joint contractures)

Section I.C.19.d.3

Non-healing burns are coded as acute burns.

Necrosis of burned skin should be coded as a non-healed burn.

Sequencing Burns / Corrosions

  • Sequence code reflecting the highest degree first when more than one burn/corrosion is documented
  • When both internal and external burns/corrosions have been documented, the circumstances of admission govern the selection of the principal diagnosis
  • When the admission is for burn injuries and other related conditions such as respiratory failure and/or smoke inhalation, the circumstances of admission govern the selection of principal diagnosis

Adverse Effects, Poisoning, Under-dosing and Toxic Effects

Codes within the category T36 – T65 range are combination codes. This would include the substance related to the poisoning, adverse or toxic effect, under-dosing and the external source. There will be no need to assign an additional external cause code in ICD-10-CM.

Adverse Effect

An appropriate code should be assigned for Adverse Effect when the drug was correctly prescribed and administered. An additional code should be assigned to show the manifestation of the Adverse Effect. Examples would be:

  • Tachycardia
  • Delirium
  • GI Bleeding
  • Renal Failure
  • Respiratory Failure
  • Nausea and vomiting


A Poisoning would constitute a reaction to the improper use of a medication via:

  • Intentional overdose
  • Error made in drug prescription
  • Interaction of drugs and alcohol
  • Nonprescription drug taken with correctly prescribed and administered drug

Poisoning codes have an associated intent shown in the 5th or 6th character.

  • Accidental
  • Intentional self-harm
  • Assault
  • Undetermined

An additional code should be assigned for all manifestations associated with poisonings.

A code for abuse or dependence should also be assigned if the provider documents a diagnosis of abuse or dependence of a drug/substance.

Coders should assign as many codes necessary to fully describe all drugs/substances and manifestations described for a particular admission.


Under-dosing is a new concept under ICD-10-CM and is defined as taking less of a drug than is recommended or prescribed by a provider or the manufacturer.

  • A code for under-dosing should never be assigned as a principal diagnosis.
  • Noncompliance (Z91.12-, Z91.13-) or complication of care (Y63.6-Y63.9) code is to be used with an under-dosing code to indicate intent, if known.

Article by Marsha Manning

Marsha Manning RHIT, CCS, AHIMA Approved ICD-10-CM/PCS Trainer, is an Inpatient Coding Consultant and Manager of Internal Education at Medical Management Plus, Inc.  Marsha has over 24 years’ experience in the coding profession and has held various positions such as DRG coordinator, Coding Supervisor and HIM Supervisor. In her current position, Marsha reviews records and assists clients with coding accuracy, compliance, education and Case Mix Index (CMI) as they relate to specific entities concerning Medicare. You may contact Marsha at This email address is being protected from spambots. You need JavaScript enabled to view it..

This material was compiled to share information. MMP, Inc. is not offering legal advice. Every reasonable effort has been taken to ensure the information is accurate and useful

green-iconWe are an environmentally conscious company, dedicated to living “green” both at work and as individuals.


1900 Twentieth Avenue South
Suite 220
Birmingham, AL 35209


This email address is being protected from spambots. You need JavaScript enabled to view it.