ICD-10 Guide

Acquired Hypothyroidism

ICD-10 Coding for Acquired Hypothyroidism(E03.9, E03.2, E03.4, E89.0)

PRIMARY SPECIALTYEndocrinology

COMPLEXITYHigh

LAST UPDATED09/15/2025

Sam Tuffun, PT, DPT

Physical Therapist | Medical Coding & Billing Contributor

Diagnosis Overview

What is Acquired Hypothyroidism?

Acquired Hypothyroidism, classified under ICD-10 codes E03.9 (Hypothyroidism, unspecified), E03.2 (Hypothyroidism due to autoimmune thyroiditis), E03.4 (Hypothyroidism due to iodine deficiency), and E89.0 (Postprocedural hypothyroidism), is a condition characterized by insufficient production of thyroid hormones by the thyroid gland. Key clinical points include: 1) It can result from autoimmune diseases, such as Hashimoto's thyroiditis; 2) Iodine deficiency is a common cause in certain populations; 3) Symptoms may include fatigue, weight gain, cold intolerance, and depression; 4) Diagnosis is typically confirmed through laboratory tests measuring TSH and free T4 levels. Typical use cases for this diagnosis code include patients presenting with symptoms of hypothyroidism and abnormal thyroid function tests. The pathophysiology involves a decrease in metabolic rate due to low thyroid hormone levels, leading to various systemic effects. Clinical presentation may vary widely, and early diagnosis is crucial to prevent complications such as cardiovascular disease and myxedema coma.

Key Clinical Considerations:

Diagnosis requires clinical evidence of hypothyroidism, including elevated TSH and low free T4 levels.
Common signs and symptoms include fatigue, weight gain, cold intolerance, dry skin, and hair loss.
Resolution criteria may include normalization of thyroid hormone levels and alleviation of symptoms following treatment.
Laboratory findings supporting diagnosis include elevated serum TSH and decreased serum free T4 levels.

Clinical Information

Clinical Criteria & Documentation Requirements

Essential documentation includes clear evidence of symptoms, laboratory results, and treatment plans.
Compliant documentation: 'Patient presents with fatigue and weight gain; TSH elevated at 8.5 mIU/L, free T4 low at 0.7 ng/dL.' Non-compliant: 'Patient has thyroid issues.'
Documentation template phrases: 'Patient diagnosed with acquired hypothyroidism based on elevated TSH and low T4 levels.'
Medical necessity documentation must justify the need for testing and treatment based on clinical presentation.

Coding Guidelines

Usage Guidelines & Examples

Use E03.9 for unspecified hypothyroidism when no specific cause is documented; use E03.2 for autoimmune causes.
Do not use these codes for congenital hypothyroidism or transient hypothyroidism due to acute illness.
Correct usage: 'Patient diagnosed with E03.2 due to Hashimoto's thyroiditis.' Incorrect: 'Patient has thyroid problems.'
Common errors include using the wrong code for the underlying cause; ensure accurate documentation of etiology.

Code Exclusions

Important Exclusions

Excluded conditions include congenital hypothyroidism (E03.1) and transient hypothyroidism due to acute illness.
Alternative codes for exclusions may include E05 for hyperthyroid conditions.
Common exclusion errors include misclassifying congenital cases as acquired; verify patient history.
Certain conditions are excluded to maintain coding specificity and accuracy in diagnosis.

Specialty Focus

Primary Specialty

Endocrinology

Specialty Applications

This diagnosis applies to adults and children with acquired hypothyroidism due to various etiologies.
Appropriate in clinical scenarios involving fatigue, weight gain, and abnormal thyroid function tests.
Applicable in both inpatient and outpatient settings, with specific considerations for endocrinology practices.
Specialty-specific coding considerations include the need for thorough documentation of thyroid function tests.

Coding Complexity

High Complexity

This diagnosis requires careful attention to:

Comprehensive clinical documentation
Accurate code selection based on clinical criteria
Proper exclusion considerations
Specialty-specific coding guidelines

Documentation

Documentation Templates

Template 1

Template: 'Acquired hypothyroidism diagnosed based on elevated TSH and low free T4 levels.'

Template 2

Template: 'Patient presents with fatigue and weight gain consistent with hypothyroidism.'

Template 3

Template: 'Diagnostic criteria met: TSH 8.5 mIU/L, free T4 0.7 ng/dL.'

Template 4

Template: 'Treatment plan includes levothyroxine therapy for acquired hypothyroidism.'

Billing Information

Billing Considerations

Ensure proper documentation for billing
Verify code specificity requirements
Check for any additional codes needed
Review payer-specific guidelines

Common Issues

Insufficient clinical documentation
Incorrect code selection
Missing supporting diagnoses
Timing and frequency documentation

Frequently Asked Questions

What documentation is required for this code?

Detailed documentation should include clinical symptoms, lab results, and treatment plans.

When should this code be used vs similar codes?

Use E03.2 for autoimmune causes and E03.9 for unspecified cases.

What are common billing issues with this code?

Reimbursement issues may arise from lack of documentation; ensure all clinical evidence is provided.

What procedures are commonly associated?

Related CPT codes include thyroid function tests and potential thyroid imaging studies.

What is Acquired Hypothyroidism?

Key Clinical Considerations:

Diagnosis requires clinical evidence of hypothyroidism, including elevated TSH and low free T4 levels.
Common signs and symptoms include fatigue, weight gain, cold intolerance, dry skin, and hair loss.
Resolution criteria may include normalization of thyroid hormone levels and alleviation of symptoms following treatment.
Laboratory findings supporting diagnosis include elevated serum TSH and decreased serum free T4 levels.

Acquired Hypothyroidism

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Template 1

Template 2

Template 3

Template 4

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

What documentation is required for this code?

When should this code be used vs similar codes?

What are common billing issues with this code?

What procedures are commonly associated?

Acquired Hypothyroidism

Diagnosis Overview

Key Clinical Considerations:

Clinical Information

Clinical Criteria & Documentation Requirements

Coding Guidelines

Usage Guidelines & Examples

Code Exclusions

Important Exclusions

Related ICD-10 Codes

Related CPT Codes

Specialty Focus

Primary Specialty

Specialty Applications

Coding Complexity

Documentation

Documentation Templates

Template 1

Template 2

Template 3

Template 4

Billing Information

Billing Considerations

Common Issues

Frequently Asked Questions

What documentation is required for this code?

When should this code be used vs similar codes?

What are common billing issues with this code?

What procedures are commonly associated?