2027 ICD-10-CM Diagnosis Code E03.9Hypothyroidism, unspecified

ICD-10-CM Codes›E00–E89›E00-E07›E03

ICD-10-CM E03.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

E03.9 is a billable ICD-10-CM diagnosis code for hypothyroidism, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 643 through 645. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

E03.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 for payment year 2027.

Code Identity

ICD-10-CM Code
E03.9
Billable Status
Yes — Valid for Submission
Code Describes
Hypothyroidism, unspecified
Short Description
Hypothyroidism, unspecified
Same as the full description in the CMS dataset.
Parent Code
E03
Other hypothyroidism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE00-E07Disorders of thyroid gland
CategoryE03Other hypothyroidism
This CodeE03.9Hypothyroidism, unspecified

Medicare Risk Adjustment (HCC)Billing

E03.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 44 — Thyroid Disorders
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired central hypothyroidism
  • Acquired hypothyroidism
  • Adult myxedema
  • Central hypothyroidism
  • Cerebral degeneration due to hypothyroidism
  • Chronic pericarditis
  • Dementia due to acquired hypothyroidism
  • Endocrine myopathy
  • Endogenous obesity
  • Hoffman syndrome
  • Hyperprolactinemia due to hypothyroidism
  • Hypertrichosis in hypothyroidism
  • Hypothyroid myopathy
  • Hypothyroid obesity
  • Hypothyroidism
  • Hypothyroidism due to infiltrative disease
  • Hypothyroidism due to sarcoidosis
  • Hypothyroidism due to thyroiditis
  • Hypothyroidism in childbirth
  • Hypothyroidism in pregnancy
  • Juvenile myxedema
  • Myasthenic syndrome due to another disorder
  • Myasthenic syndrome due to hypothyroidism
  • Myxedema
  • Myxedema cerebellar degeneration
  • Myxedema neuropathy
  • Obesity by contributing factors
  • Obesity of endocrine origin
  • Pericarditis secondary to myxedema
  • Premature puberty due to hypothyroidism
  • Primary hypothyroidism
  • Pseudohypertrophy of muscle
  • Secondary cerebellar degeneration
  • Severe hypothyroidism
  • Subclinical disease AND/OR syndrome
  • Subclinical hypothyroidism
  • Subclinical hypothyroidism in pregnancy
  • Thyroid disease in pregnancy
  • Transient decreased production of T>4<

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to E03.9: its own notes plus those printed at E03 and Chapter 4. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Myxedema NOS

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From E03 Other hypothyroidism applies to 8 codes
  • iodine-deficiency related hypothyroidism (E00-E02)
  • postprocedural hypothyroidism (E89.0)
From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)

Notes

General instructions on how these codes are used.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name E03.9, its category, or a range that includes it.

Applicable To 1

These notes mention E03.9.

  • Z83.4 Family history of other endocrine, nutritional and metabolic diseases
    Conditions classifiable to E00-E07, E15-E88 names E00-E07, which includes this code

Excludes1 1

These codes carry an Excludes1 note naming E03.9: they are not reported together with it, unless the two conditions are unrelated.

  • L98.5 Mucinosis of the skin
    myxedema (E03.9)

Code First 7

These codes say to code first a condition named in the note, and E03.9 is one of the conditions named.

  • G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema
    hypothyroidism (E03.-) names E03.-, which includes this code
  • H28 Cataract in diseases classified elsewhere
    myxedema (E03.-) names E03.-, which includes this code
  • D63.8 Anemia in other chronic diseases classified elsewhere
    hypothyroidism (E00.0-E03.9) names E00.0-E03.9, which includes this code
  • F02 Dementia in other diseases classified elsewhere
    hypothyroidism, acquired (E00-E03.-) names E00-E03, which includes this code
  • G32.8 Other specified degenerative disorders of nervous system in diseases classified elsewhere
    cerebral degeneration (due to) hypothyroidism (E00.0-E03.9) names E00.0-E03.9, which includes this code
  • G63 Polyneuropathy in diseases classified elsewhere
    endocrine disease, except diabetes (E00-E07, E15-E16, E20-E34) names E00-E07, which includes this code
  • M14.8 Arthropathies in other specified diseases classified elsewhere
    hypothyroidism (E00-E03) names E00-E03, which includes this code

Code Also 1

These codes say E03.9 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • I27.29 Other secondary pulmonary hypertension
    hypothyroidism (E00-E03) names E00-E03, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR END001
Thyroid disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hypothyroidism

    a syndrome that results from abnormally low secretion of thyroid hormones from the thyroid gland, leading to a decrease in basal metabolic rate. in its most severe form, there is accumulation of mucopolysaccharides in the skin and edema, known as myxedema. it may be primary or secondary due to other pituitary disease, or hypothalamic dysfunction.

Patient EducationClinical

Hypothyroidism

Hypothyroidism, or underactive thyroid, happens when your thyroid gland doesn't make enough thyroid hormones to meet your body's needs.

The full article covers:

  • What is hypothyroidism?
  • What causes hypothyroidism?
  • Who is at risk for hypothyroidism?
  • What are the symptoms of hypothyroidism?
  • What other problems can hypothyroidism cause?
  • How is hypothyroidism diagnosed?
  • What are the treatments for hypothyroidism?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E03.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
244.9 Hypothyroidism NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About E03.9Overview

What is the ICD-10 code for hypothyroidism, unspecified?

The ICD-10-CM code for hypothyroidism, unspecified is E03.9 (sometimes written as E039). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is E03.9 (Other hypothyroidism) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report hypothyroidism, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does E03.9 group to?

When hypothyroidism, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 644, 645, 643, with relative weights from 0.7461 to 1.6138 depending on complications. Higher weights mean higher Medicare reimbursement.

Can E03.9 be reported with E89.0?

Not as a rule. The Excludes1 note at E03, which applies to E03.9, lists "postprocedural hypothyroidism (E89.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of E03.9?

Under the General Equivalence Mappings, hypothyroidism, unspecified converts to ICD-9-CM 244.9 (hypothyroidism NOS). The mapping is a direct match.

Does E03.9 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: E03.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 (Thyroid Disorders).