ICD10BillableValid for clinical use

ICD-10 Code E03.3: Postinfectious hypothyroidism

E03.3 is a billable ICD-10 diagnosis code used to classify Postinfectious hypothyroidism in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

When is it used?

  • May be used when a clinician documents postinfectious hypothyroidism in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
4Endocrine, nutritional and metabolic diseases (E00-E89)
block
E00-E07Disorders of thyroid gland
category
E03Other hypothyroidism
currentE03

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

EndocrinologistGeneral Physician

Related tests

TSH
Commonly reviewed in hypothyroidism evaluation.
Free T4
Often reviewed alongside TSH in thyroid assessment.
Anti-thyroid peroxidase antibody
May be relevant when autoimmune thyroid disease is being considered.

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
E03.3

Common synonyms

Postinfectious hypothyroidism

Frequently asked questions

Code details

CodeE03.3
SystemICD10
Display namePostinfectious hypothyroidism
ChapterEndocrine, nutritional and metabolic diseases (E00-E89)
BlockDisorders of thyroid gland

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Hypothyroidism(acquired)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code E03.3 for Postinfectious hypothyroidism | HealthAssure