2027 ICD-10-CM Diagnosis Code O48.1Prolonged pregnancy

ICD-10-CM Codes›O00-O9A›O30-O48›O48

ICD-10-CM O48.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

O48.1 is a billable ICD-10-CM diagnosis code for prolonged pregnancy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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). Coders also document this condition as postmaturity of fetus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Prolonged pregnancy.

Code Identity

ICD-10-CM Code
O48.1
Billable Status
Yes — Valid for Submission
Code Describes
Prolonged pregnancy
Short Description
Prolonged pregnancy
Same as the full description in the CMS dataset.
Parent Code
O48
Late pregnancy

Code Classification

ChapterO00-O9APregnancy, childbirth and the puerperium
SectionO30-O48Maternal care related to the fetus and amniotic cavity and possible delivery problems
CategoryO48Late pregnancy
This CodeO48.1Prolonged pregnancy

Code EditsBilling

Medicare Code Editor checks that affect claim validity for O48.1.

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.

  • Postmaturity of fetus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to O48.1: its own notes plus those printed at Chapter 15. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Pregnancy which has advanced beyond 42 completed weeks gestation

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 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.

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 PRG022
Prolonged pregnancy
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Pregnancy, Prolonged

    a term used to describe pregnancies that exceed the upper limit of a normal gestational period. in humans, a prolonged pregnancy is defined as one that extends beyond 42 weeks (294 days) after the first day of the last menstrual period (menstruation), or birth with gestational age of 41 weeks or more.

Patient EducationClinical

Childbirth Problems

Childbirth is the process of giving birth to a baby. It includes labor and delivery. Usually everything goes well, but problems can happen. They may cause a risk to the mother, baby, or both. Some of the more common childbirth problems include:

Read the full article at MedlinePlus

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

Convert O48.1 to ICD-9-CMHistory

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

ICD-9-CM
645.23 Prolonged preg-antepar
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 O48.1Overview

What is the ICD-10 code for prolonged pregnancy?

The ICD-10-CM code for prolonged pregnancy is O48.1 (sometimes written as O481). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is O48.1 (Late pregnancy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report prolonged pregnancy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does O48.1 group to?

When prolonged pregnancy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 833, 832, 831, 819, 818, 817, with relative weights from 0.5000 to 1.7586 depending on complications. Higher weights mean higher Medicare reimbursement.

Who can O48.1 be reported for?

The Medicare Code Editor checks prolonged pregnancy 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 O48.1?

Under the General Equivalence Mappings, prolonged pregnancy converts to ICD-9-CM 645.23 (prolonged preg-antepar). The mapping is approximate, so confirm the match fits the documentation.