2026 ICD-10-CM Diagnosis Code E20.812Autoimmune hypoparathyroidism

ICD-10-CM CodesE00–E89E20-E35E20

ICD-10-CM E20.812
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E20.812 is a billable ICD-10-CM diagnosis code for autoimmune hypoparathyroidism. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E20.812
Billable Status
Yes — Valid for Submission
Code Describes
Autoimmune hypoparathyroidism
Short Description
Autoimmune hypoparathyroidism
Same as the full description in the CMS dataset.
Parent Code
Hypoparathyroidism due to impaired parathyroid hormone secretion

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE20-E35Disorders of other endocrine glands
CategoryE20Hypoparathyroidism
This CodeE20.812Autoimmune hypoparathyroidism

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autoimmune hypoparathyroidism

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Code First

  • , if applicable, underlying condition such as:
  • autoimmune polyglandular failure E31.0
  • Schmidt's syndrome E31.0

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Hypoparathyroidism
      • autoimmune

Clinical ClassificationClinical

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

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement E20.812 replaces the following previously assigned code(s):

  • E20.8 - Other hypoparathyroidism
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E20.812Overview

Is E20.812 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report autoimmune hypoparathyroidism on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E20.812 group to?

When autoimmune hypoparathyroidism is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.