ICD10BillableValid for clinical use
ICD-10 Code E05.31: Thyrotoxicosis from ectopic thyroid tissue with thyrotoxic crisis or storm
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).
šClinical overview
This ICD-10 code is commonly used when documentation describes thyrotoxicosis from a toxic single thyroid nodule or from ectopic thyroid tissue. The most accurate code depends on the documented hormone source and whether thyrotoxic crisis or storm is present.
When is it used?
- May be used when a clinician documents thyrotoxicosis from ectopic thyroid tissue with thyrotoxic crisis or storm 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.
š©ŗClinical context
When commonly used
- Endocrinology, emergency, inpatient, and utilization-review workflows where hyperthyroid symptoms, thyroid-storm concern, or focal thyroid-hormone overproduction is part of the assessment.
- Coding workflows where the chart distinguishes toxic-single-nodule thyrotoxicosis from ectopic-thyroid-source thyrotoxicosis and documents crisis-versus-non-crisis severity.
Common workup
- Common related testing on this page includes TSH, Free T4, Free T3.
Common management context
- Evaluation often includes TSH and thyroid-hormone review, symptom assessment for palpitations, tremor, weight loss, heat intolerance, or altered mental status, and endocrine or acute-care management planning.
- Documentation usually becomes more specific when the chart identifies a toxic single thyroid nodule versus ectopic thyroid tissue, and clarifies whether thyrotoxic crisis or storm is present.
- Specialist context already linked on this page includes Endocrinologist, General Physician.
šKey distinctions
Important notes
- This ICD-10 family captures a narrow thyrotoxicosis branch driven by focal hormone source detail rather than diffuse goiter, multinodular goiter, factitia, or unspecified hyperthyroid states.
- Source detail and crisis-versus-non-crisis severity are what drive final code specificity inside this family.
- Thyrotoxicosis from ectopic thyroid tissue with crisis or storm is coded separately from the non-crisis presentation and from toxic-single-nodule thyrotoxicosis.
- Crisis-or-storm documentation matters here because thyrotoxic crisis is coded separately from otherwise similar thyrotoxicosis without crisis.
- Documentation that describes thyrotoxicosis in this branch is coded differently depending on whether the hormone excess is tied to a toxic single nodule or ectopic thyroid tissue, and whether thyroid storm is documented.
Related codes to consider
E05.30Thyrotoxicosis from ectopic thyroid tissue without thyrotoxic crisis or storm
Related thyrotoxicosis ICD-10 code; documentation often becomes more specific when the chart identifies toxic single nodule versus ectopic thyroid tissue, and whether thyrotoxic crisis or storm is present.
Code hierarchy
chapter
4Endocrine, nutritional and metabolic diseases (E00-E89)
block
E00-E07Disorders of thyroid gland
category
E05Thyrotoxicosis [hyperthyroidism]
category
E05.3Thyrotoxicosis from ectopic thyroid tissue
currentE05.3
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 hyperthyroidism evaluation.
Free T4
Often reviewed alongside TSH in thyroid assessment.
Free T3
May help clarify thyroid hormone excess in hyperthyroid states.
Related codes
Sibling codes
Coverage-related procedures and services
CPT 00532high
ANESTHESIA FOR ACCESS TO CENTRAL VENOUS CIRCULATION
Source: CMS coverage guidance
CPT 01420high
ANESTHESIA FOR ALL CAST APPLICATIONS, REMOVAL, OR REPAIR INVOLVING KNEE JOINT
Source: CMS coverage guidance
CPT 01730high
ANESTHESIA FOR ALL CLOSED PROCEDURES ON HUMERUS AND ELBOW
Source: CMS coverage guidance
CPT 01380high
ANESTHESIA FOR ALL CLOSED PROCEDURES ON KNEE JOINT
Source: CMS coverage guidance
CPT 01820high
ANESTHESIA FOR ALL CLOSED PROCEDURES ON RADIUS, ULNA, WRIST, OR HAND BONES
Source: CMS coverage guidance
CPT 00322high
ANESTHESIA FOR ALL PROCEDURES ON ESOPHAGUS, THYROID, LARYNX, TRACHEA AND LYMPHATIC SYSTEM OF NECK; NEEDLE BIOPSY OF THYROID
Source: CMS coverage guidance
Coding guidelines
Common synonyms
Thyrotoxicosis from ectopic thyroid tissue with thyrotoxic crisis or storm
Frequently asked questions
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.