2027 ICD-10-CM Diagnosis Code O45.91Premature separation of placenta, unspecified, first trimester
ICD-10-CM Codes›O00-O9A›O30-O48›O45
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Not Chronic
O45.91 is a billable ICD-10-CM diagnosis code for premature separation of placenta, unspecified, first trimester. 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. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 253 closely related codes. 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 Early, first or unspecified trimester hemorrhage; and Maternal care related to disorders of the placenta and placental implantation.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O45.91.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O45.91: its own notes plus those printed at 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.
- 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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- 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.
- 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 O45.91, its category, or a range that includes it.
Excludes1 3
These codes carry an Excludes1 note naming O45.91: they are not reported together with it, unless the two conditions are unrelated.
- O46 Antepartum hemorrhage, not elsewhere classifiedpremature separation of placenta [abruptio placentae] (O45.-) names O45.-, which includes this code
- O67 Labor and delivery complicated by intrapartum hemorrhage, not elsewhere classifiedpremature separation of placenta [abruptio placentae] (O45.-) names O45.-, which includes this code
- O99.1 Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperiumhemorrhage with coagulation defects (O45.-, O46.0-, O67.0, O72.3) names O45.-, which includes this code
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Placental Abruption
placental separation from the uterus with bleeding (concealed or vaginal) before fetal birth, with or without maternal/fetal compromise. (revitalize)
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 O45.91 to ICD-9-CMHistory
Code HistoryHistory
Questions About O45.91Overview
What is the ICD-10 code for premature separation of placenta, unspecified, first trimester?
The ICD-10-CM code for premature separation of placenta, unspecified, first trimester is O45.91 (sometimes written as O4591). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O45.91 (Premature separation of placenta, unspecified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report premature separation of placenta, unspecified, first trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O45.91 group to?
When premature separation of placenta, unspecified, first trimester 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.
Is O45.91 a CC or MCC?
CMS lists O45.91 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 253 closely related codes in its exclusion list.
Who can O45.91 be reported for?
The Medicare Code Editor checks premature separation of placenta, unspecified, first trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
