2026 ICD-10-CM Diagnosis Code O90.5Postpartum thyroiditis

ICD-10-CM Codes›O00-O9A›O85-O92›O90

ICD-10-CM O90.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O90.5 is a billable ICD-10-CM diagnosis code for postpartum thyroiditis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complications specified during the puerperium and Thyroid disorders.

Code Identity

ICD-10-CM Code
O90.5
Billable Status
Yes — Valid for Submission
Code Describes
Postpartum thyroiditis
Short Description
Postpartum thyroiditis
Same as the full description in the CMS dataset.
Parent Code
O90
Complications of the puerperium, not elsewhere classified

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO85-O92Complications predominantly related to the puerperium
CategoryO90Complications of the puerperium, not elsewhere classified
This CodeO90.5Postpartum thyroiditis

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O90.5.

Maternity diagnoses
The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Postpartum thyroiditis

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.

    • Puerperal, puerperium(complicated by, complications)
      • thyroiditis
    • Thyroiditis
      • postpartum, puerperal

Clinical ClassificationClinical

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

CCSR PRG027
Complications specified during the puerperium
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR END001
Thyroid disorders
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Postpartum Thyroiditis

    transient autoimmune thyroiditis occurring in the postpartum period. it is characterized by the presence of high titers of autoantibodies against thyroid peroxidase and thyroglobulin. clinical signs include the triphasic thyroid hormone pattern: beginning with thyrotoxicosis, followed with hypothyroidism, then return to euthyroid state by 1 year postpartum.

Patient EducationClinical

Postpartum Care

Taking home a new baby is one of the happiest times in a woman's life. But it also presents both physical and emotional challenges. :

Read the full article at MedlinePlus

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

Convert O90.5 to ICD-9-CMHistory

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

ICD-9-CM
648.12 Thyroid dysfun-del w p/p
Approximate The match is approximate rather than exact.
ICD-9-CM
648.14 Thyroid dysfunc-postpart
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About O90.5Overview

Is O90.5 (Complications of the puerperium, not elsewhere classified) a billable code?

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

Who can O90.5 be reported for?

The Medicare Code Editor checks postpartum thyroiditis against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.

What is the ICD-9 equivalent of O90.5?

Under the General Equivalence Mappings, postpartum thyroiditis converts to ICD-9-CM 648.12 (thyroid dysfun-del w p/p) and 648.14 (thyroid dysfunc-postpart). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.