2027 ICD-10-CM Diagnosis Code O99.019Anemia complicating pregnancy, unspecified trimester
ICD-10-CM Codes›O00-O9A›O94-O9A›O99
- Billable — Valid for Submission
- Not Chronic
O99.019 is a billable ICD-10-CM diagnosis code for anemia complicating pregnancy, unspecified 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. 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
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O99.019.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Alpha thalassemia trait in mother complicating pregnancy
- Anemia in mother complicating pregnancy, childbirth AND/OR puerperium
- Anemia of pregnancy
- Aplastic anemia associated with pregnancy
- Beta thalassemia major in mother complicating pregnancy
- Beta thalassemia trait in mother complicating pregnancy
- Hemolytic anemia of pregnancy
- Heterozygous hemoglobinopathy
- Heterozygous thalassemia
- Iron deficiency anemia of pregnancy
- Macrocytic anemia of pregnancy
- Megaloblastic anemia due to folate deficiency due to increased requirement
- Megaloblastic anemia due to folate deficiency in pregnancy and lactation
- Megaloblastic anemia due to impaired absorption of folate
- Megaloblastic anemia due to pregnancy
- Nutritional anemia of pregnancy
- Sickle cell trait
- Sickle cell trait in mother complicating pregnancy
- Thalassemia in mother complicating pregnancy
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O99.019: its own notes plus those printed at O99.0, O99, and Chapter 15. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- conditions which complicate the pregnant state, are aggravated by the pregnancy or are a main reason for obstetric care
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 to identify specific 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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Anemia
If you have anemia, your blood does not carry enough oxygen to the rest of your body. The most common cause of anemia is not having enough iron. Your body needs iron to make hemoglobin. Hemoglobin is an iron-rich protein that gives the red color to blood. It carries oxygen from the lungs to the rest of the body.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert O99.019 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About O99.019Overview
What is the ICD-10 code for anemia complicating pregnancy, unspecified trimester?
The ICD-10-CM code for anemia complicating pregnancy, unspecified trimester is O99.019 (sometimes written as O99019). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O99.019 (Anemia complicating pregnancy) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report anemia complicating pregnancy, unspecified trimester on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O99.019 group to?
When anemia complicating pregnancy, unspecified 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.
Who can O99.019 be reported for?
The Medicare Code Editor checks anemia complicating pregnancy, unspecified trimester against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
Can O99.019 be reported with O90.81?
Not as a rule. The Excludes1 note at O99.0, which applies to O99.019, lists "anemia arising in the puerperium (O90.81)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
