2026 ICD-10-CM Diagnosis Code O98.511Other viral diseases complicating pregnancy, first trimester

ICD-10-CM Codes›O00-O9A›O94-O9A›O98

ICD-10-CM O98.511
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O98.511 is a billable ICD-10-CM diagnosis code for other viral diseases complicating pregnancy, first trimester. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 817 through 819, 831 through 833. 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 Other specified complications in pregnancy.

Code Identity

ICD-10-CM Code
O98.511
Billable Status
Yes — Valid for Submission
Code Describes
Other viral diseases complicating pregnancy, first trimester
Short Description
Other viral diseases complicating pregnancy, first trimester
Same as the full description in the CMS dataset.
Parent Code
O98.51
Other viral diseases complicating pregnancy

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO94-O9AOther obstetric conditions, not elsewhere classified
CategoryO98Maternal infectious and parasitic diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
This CodeO98.511Other viral diseases complicating pregnancy, first trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O98.511.

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).

Clinical ClassificationClinical

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

CCSR PRG028
Other specified complications in pregnancy
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Infections and Pregnancy

During pregnancy, some common infections such as the common cold or a skin infection do not usually cause serious problems. Some infections, such as the flu, can be more severe when you're pregnant. But other infections can be harmful to you, your fetus, or both.

The full article covers:

  • How can infections affect your pregnancy?
  • What infections can be harmful during pregnancy?
  • What are the symptoms of an infection during pregnancy?
  • What are the treatments for infections during pregnancy?
  • Can infections during pregnancy be prevented?

Read the full article at MedlinePlus

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

Convert O98.511 to ICD-9-CMHistory

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

ICD-9-CM
647.61 Oth viral dis-delivered
Approximate The match is approximate rather than exact.
ICD-9-CM
647.63 Oth viral dis-antepartum
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 O98.511Overview

Is O98.511 (Other viral diseases complicating pregnancy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other viral diseases complicating pregnancy, first trimester on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does O98.511 group to?

When other viral diseases complicating pregnancy, first trimester is the principal diagnosis on an inpatient stay, it groups to MS-DRG 817, 818, 819, 831, 832, 833, with relative weights from 0.5229 to 1.6880 depending on complications. Higher weights mean higher Medicare reimbursement.

Who can O98.511 be reported for?

The Medicare Code Editor checks other viral diseases complicating pregnancy, first trimester 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 O98.511?

Under the General Equivalence Mappings, other viral diseases complicating pregnancy, first trimester converts to ICD-9-CM 647.61 (oth viral dis-delivered) and 647.63 (oth viral dis-antepartum). 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.