2027 ICD-10-CM Diagnosis Code E03.3Postinfectious hypothyroidism
ICD-10-CM Codes›E00–E89›E00-E07›E03
- Billable — Valid for Submission
- Chronic Condition
E03.3 is a billable ICD-10-CM diagnosis code for postinfectious hypothyroidism. 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. Coders also document this condition as post-infectious hypothyroidism. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.
E03.3 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
Code Classification
Medicare Risk Adjustment (HCC)Billing
E03.3 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.
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.
- Post-infectious hypothyroidism
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to E03.3: 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.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Notes
General instructions on how these codes are used.
- 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 E03.3, its category, or a range that includes it.
Applicable To 1
These notes mention E03.3.
- Z83.4 Family history of other endocrine, nutritional and metabolic diseases
Code First 7
These codes say to code first a condition named in the note, and E03.3 is one of the conditions named.
- G13.2 Systemic atrophy primarily affecting the central nervous system in myxedemahypothyroidism (E03.-) names E03.-, which includes this code
- H28 Cataract in diseases classified elsewheremyxedema (E03.-) names E03.-, which includes this code
- D63.8 Anemia in other chronic diseases classified elsewhere
- F02 Dementia in other diseases classified elsewhere
- G32.8 Other specified degenerative disorders of nervous system in diseases classified elsewhere
- G63 Polyneuropathy in diseases classified elsewhere
- M14.8 Arthropathies in other specified diseases classified elsewhere
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.
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 E03.3 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E03.3Overview
What is the ICD-10 code for postinfectious hypothyroidism?
The ICD-10-CM code for postinfectious hypothyroidism is E03.3 (sometimes written as E033). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is E03.3 (Other hypothyroidism) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report postinfectious hypothyroidism on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does E03.3 group to?
When postinfectious hypothyroidism 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 E03.3 be reported with E89.0?
Not as a rule. The Excludes1 note at E03, which applies to E03.3, 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 E03.3?
Under the General Equivalence Mappings, postinfectious hypothyroidism converts to ICD-9-CM 244.8 (acquired hypothyroid NEC). The mapping is approximate, so confirm the match fits the documentation.
Does E03.3 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: E03.3 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 (Thyroid Disorders).
