2026 ICD-10-CM Diagnosis Code O30.012Twin pregnancy, monochorionic/monoamniotic, second trimester

ICD-10-CM Codes›O00-O9A›O30-O48›O30

ICD-10-CM O30.012
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

O30.012 is a billable ICD-10-CM diagnosis code for twin pregnancy, monochorionic/monoamniotic, second 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 Multiple gestation.

Code Identity

ICD-10-CM Code
O30.012
Billable Status
Yes — Valid for Submission
Code Describes
Twin pregnancy, monochorionic/monoamniotic, second trimester
Short Description
Twin pregnancy, monochorionic/monoamniotic, second trimester
Same as the full description in the CMS dataset.
Parent Code
O30.01
Twin pregnancy, monochorionic/monoamniotic

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO30-O48Maternal care related to the fetus and amniotic cavity and possible delivery problems
CategoryO30Multiple gestation
This CodeO30.012Twin pregnancy, monochorionic/monoamniotic, second trimester

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O30.012.

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 PRG012
Multiple gestation
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Twins, Triplets, Multiple Births

If you are pregnant with more than one baby, you are far from alone. Multiple births are up in the United States. More women are having babies after age 30 and more are taking fertility drugs. Both boost the chance of carrying more than one baby. A family history of twins also makes multiples more likely.

Read the full article at MedlinePlus

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

Convert O30.012 to ICD-9-CMHistory

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

ICD-9-CM
651.01 Twin pregnancy-delivered
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
651.03 Twin pregnancy-antepart
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
V91.01 Twin gest-monochr/monoam
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 O30.012Overview

Is O30.012 (Twin pregnancy, monochorionic/monoamniotic) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report twin pregnancy, monochorionic/monoamniotic, second trimester on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does O30.012 group to?

When twin pregnancy, monochorionic/monoamniotic, second 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 O30.012 be reported for?

The Medicare Code Editor checks twin pregnancy, monochorionic/monoamniotic, second 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 O30.012?

Under the General Equivalence Mappings, twin pregnancy, monochorionic/monoamniotic, second trimester converts to ICD-9-CM 651.01 (twin pregnancy-delivered), 651.03 (twin pregnancy-antepart), and V91.01 (twin gest-monochr/monoam). 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.