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E03.3 ICD-10-CM Code: Postinfectious hypothyroidism

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
2 Excludes1
Risk adjustment
RxHCC V08 category 44

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 643 — ENDOCRINE DISORDERS WITH MCC (MDC 10)
  • MS-DRG 644 — ENDOCRINE DISORDERS WITH CC (MDC 10)
  • MS-DRG 645 — ENDOCRINE DISORDERS WITHOUT CC/MCC (MDC 10)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for E03.3 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on E03.3 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from E03

Coder workflow for E03.3

MedCoder structured workflow — derived from this code’s own official record

Before you code E03.3

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with E03.3. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in E03.3’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewE89.0

Consider E03.3. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).

Official instructions as workflow

  • Excludes1 — check before selecting E03.3(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with E03.3: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareE89.0

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition E03.3 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewE89.0

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Postinfectious hypothyroidism is a billable ICD-10-CM diagnosis code (E03.3).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (1)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name E03.3 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 7 Code First instructions across 5 chapters: D63.8 — Anemia in other chronic diseases classified elsewhere (via E03.-), F02 — Dementia in other diseases classified elsewhere (via E03.-), G13.2 — Systemic atrophy primarily affecting the central nervous system in myxedema (via E03.-), G32.8 — Other specified degenerative disorders of nervous system in diseases classified elsewhere (via E03.-), G63 — Polyneuropathy in diseases classified elsewhere (via E03.-), H28 — Cataract in diseases classified elsewhere (via E03.-), M14.8 — Arthropathies in other specified diseases classified elsewhere (via E03.-).

Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.

Referenced by 1 Code Also instruction: I27.29 — Other secondary pulmonary hypertension (via E03.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 3 MS-DRGs: DRG 643 (MDC 10), DRG 644 (MDC 10), DRG 645 (MDC 10).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):END001 — Thyroid disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Thyroid disorders).

E00.2 — Congenital iodine-deficiency syndrome, mixed type, E00.9 — Congenital iodine-deficiency syndrome, unspecified, E01.0 — Iodine-deficiency related diffuse (endemic) goiter, E01.1 — Iodine-deficiency related multinodular (endemic) goiter, E01.2 — Iodine-deficiency related (endemic) goiter, unspecified, E01.8 — Other iodine-deficiency related thyroid disorders and allied conditions, E02 — Subclinical iodine-deficiency hypothyroidism, E03.0 — Congenital hypothyroidism with diffuse goiter, E03.1 — Congenital hypothyroidism without goiter, E03.2 — Hypothyroidism due to medicaments and other exogenous substances, E03.4 — Atrophy of thyroid (acquired), E03.5 — Myxedema coma, E03.8 — Other specified hypothyroidism, E03.9 — Hypothyroidism, unspecified, E04.0 — Nontoxic diffuse goiter, E04.1 — Nontoxic single thyroid nodule, E04.2 — Nontoxic multinodular goiter, E04.8 — Other specified nontoxic goiter, E04.9 — Nontoxic goiter, unspecified, E05.00 — Thyrotoxicosis with diffuse goiter without thyrotoxic crisis or storm, +35 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Hypothyroidism”; these codes share that main term but sit in a different category of the Tabular List.

E01.8 — Other iodine-deficiency related thyroid disorders and allied conditions (iodine-deficiency), E02 — Subclinical iodine-deficiency hypothyroidism (iodine-deficiency, subclinical), E89.0 — Postprocedural hypothyroidism (postsurgical), P72.2 — Other transitory neonatal disorders of thyroid function, not elsewhere classified (neonatal, transitory)

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Lipid Panel, Thyroid Stimulating Hormone (TSH)

Contextual Map

Every relationship of E03.3 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run E03.3 with these 8 related codes in Claim Check

Hierarchy

Referenced by Code First instructions

Referenced by Code Also instructions

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 10 — Endocrine, Nutritional and Metabolic Diseases and Disorders[MDC crossing]: “Endocrine, Nutritional and Metabolic Diseases and Disorders — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 5,008 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Hypothyroidism (acquired), postinfectious[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "E03.3 — Postinfectious hypothyroidism." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/e03.3-postinfectious-hypothyroidism

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Postinfectious hypothyroidism

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to E03.3 in its code family, with their registry titles.

View all codes in the E03 family