2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O90.5 is a billable ICD-10-CM diagnosis code for postpartum thyroiditis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 769, 776. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O90.5: its own notes plus those printed at block O85-O92 and Chapter 15. 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.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • supervision of normal pregnancy (Z34.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block O85-O92 Complications predominantly related to the puerperium applies to 114 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • puerperal osteomalacia (M83.0)
From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • mental and behavioral disorders associated with the puerperium (F53.-)
  • obstetrical tetanus (A34)
  • postpartum necrosis of pituitary gland (E23.0)
  • puerperal osteomalacia (M83.0)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.

Notes

General instructions on how these codes are used.

From Chapter 15 (O00-O9A) Pregnancy, childbirth and the puerperium applies to 2,481 codes
  • CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
  • Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
  • Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
  • 1st trimester- less than 14 weeks 0 days
  • 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
  • 3rd trimester- 28 weeks 0 days until delivery

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name O90.5, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming O90.5: they are not reported together with it, unless the two conditions are unrelated.

  • E06 Thyroiditis
    postpartum thyroiditis (O90.5)

Excludes2 1

These codes carry an Excludes2 note naming O90.5: its condition is not part of those codes, and both may be reported when the patient has both.

  • O99.2 Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperium
    postpartum thyroiditis (O90.5)

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 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About O90.5Overview

What is the ICD-10 code for postpartum thyroiditis?

The ICD-10-CM code for postpartum thyroiditis is O90.5 (sometimes written as O905). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does O90.5 group to?

When postpartum thyroiditis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 769, 776, with relative weights from 0.6718 to 1.6666 depending on complications. Higher weights mean higher Medicare reimbursement.

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.