Obstetric Coding in ICD-10-CM/PCS

By Ann Barta, MSA, RHIA

ICD-10-CM/PCS will capture a greater level of specificity for obstetric coding. This article highlights some of the new features in coding obstetric cases with ICD-10-CM/PCS.

OB Diagnoses Coding with ICD-10-CM

Obstetric cases require diagnosis codes from chapter 15 of ICD-10-CM, “Pregnancy, Childbirth, and the Puerperium.” It includes categories O00–O9A arranged in the following blocks:

  • O00–O08, Pregnancy with abortive outcome
  • O09, Supervision of high-risk pregnancy
  • O10–O16, Edema, proteinuria, and hypertensive disorders in pregnancy, childbirth, and the puerperium
  • O20–O29, Other maternal disorders predominantly related to pregnancy
  • O30–O48, Maternal care related to the fetus and amniotic cavity and possible delivery problems
  • O60–O77, Complications of labor and delivery
  • O80, O82, Encounter for delivery
  • O85–O92, Complications predominantly related to the puerperium
  • O94–O9A, Other obstetric conditions, not elsewhere classified

Similar to ICD-9-CM, ICD-10-CM obstetric codes in chapter 15 have sequencing priority over codes from other chapters. Additional codes from other chapters may be used in addition to chapter 15 codes to further specify conditions.

The episode of care (delivered, antepartum, postpartum) is no longer a secondary axis of classification for obstetric codes. Instead, the majority of codes have a final character identifying the trimester of pregnancy in which the condition occurred.

Because certain obstetric conditions or complications occur during certain trimesters, not all conditions include codes for all three trimesters.

For example, preterm labor without delivery can only occur in either the second or third trimester; therefore the subcategory O60.0, Preterm labor without delivery, is further subdivided as O60.00, Preterm labor without delivery, unspecified trimester; O60.02, Preterm labor without delivery, second trimester; and O60.03, Preterm labor without delivery, third trimester.

Additionally, trimester is not a component of some obstetric codes because the condition either always occurs in a specific trimester or the trimester concept is not applicable. Examples of ICD-10-CM codes not classified by trimester are O62.1, Secondary uterine inertia, O63.1, Prolonged second stage (of labor), and O70.1, Second degree perineal laceration during delivery.

The assignment of the final character for trimester is based on the trimester for the current admission or encounter. This guideline applies to the assignment of trimester for pre-existing conditions as well as those that develop during or are due to the pregnancy.

Some categories in chapter 15 also classify the obstetrical condition as “in childbirth” or “in puerperium.” For example, the following codes are provided for category O25, Malnutrition in pregnancy, childbirth and the puerperium:

  • O25.1, Malnutrition in pregnancy
  • O25.10, Malnutrition in pregnancy, unspecified trimester
  • O25.11, Malnutrition in pregnancy, first trimester
  • O25.12, Malnutrition in pregnancy, second trimester
  • O25.13, Malnutrition in pregnancy, third trimester
  • O25.2, Malnutrition in childbirth
  • O25.3, Malnutrition in the puerperium

If a delivery occurs during an admission and there is an “in childbirth” option for the obstetric complication being coded, the “in childbirth” code should be assigned. If the complication occurs after delivery, the “in puerperium” code should be assigned if available.

A note at the beginning of chapter 15 defines trimesters. Trimesters are counted from the first day of the last menstrual period. They are defined as follows:

  • First trimester: less than 14 weeks 0 days
  • Second trimester: 14 weeks 0 days to less than 28 weeks 0 days
  • Third trimester: 28 weeks 0 days until delivery

Similar to ICD-9-CM, multiple gestations are classified in ICD-10-CM:

  • O30.0, Twin pregnancy
  • O30.1, Triplet pregnancy
  • O30.2, Quadruplet pregnancy
  • O30.8, Other multiple gestation
  • O30.9, Multiple gestation, unspecified

Codes from this category also require either a fifth or sixth character specifying the trimester. Code O30.0, Twin pregnancy, is further classified by whether the twin pregnancy is monoamniotic/monochorionic, conjoined twins, other twin pregnancy, or unspecified twin pregnancy.

Certain codes in chapter 15 require the use of a seventh character extension to identify the fetus in a multiple gestation that is affected by the condition being coded. The following guideline appears under any ICD-10-CM category requiring a seventh character extension:

“One of the following seventh characters is to be assigned to each code under this category. Seventh character 0 is for single gestations and multiple gestations where the fetus is unspecified. Seventh characters 1 through 9 are for cases of multiple gestations to identify the fetus for which the code applies. The appropriate code from category O30, Multiple gestation, must also be assigned when assigning a code from this category that has a seventh character of 1 through 9.

  • 0 not applicable or unspecified
  • 1 fetus 1
  • 2 fetus 2
  • 3 fetus 3
  • 4 fetus 4
  • 5 fetus 5
  • 9 other fetus”

Normal deliveries are classified to O80, Encounter for full-term uncomplicated delivery. A note in the tabular provides directions for the use of this code as follows: “Delivery requiring minimal or no assistance, with or without episiotomy, without fetal manipulation (i.e., rotation version) or instrumentation [forceps] of a spontaneous, cephalic, vaginal, full-term, single, live-born infant. This code must be accompanied by a delivery code from the appropriate procedure classification.” Similar to the use of 650 in ICD-9-CM, code O80 is always the principal diagnosis and is not to be used with any other code from chapter 15.

Outcome of delivery codes (Z37.0–Z37.9) are intended for use as an additional code to identify the outcome of delivery on the mother’s records. These codes are not to be used on subsequent records or on the newborn record.

Seven Characters of an Obstetrics Code

Character 1

Character 2

Character 3

Character 4

Character 5

Character 6

Character 7


Body System

Root Operation

Body Part




OB Procedure Coding with ICD-10-PCS

The obstetrics section is one of 16 sections in ICD-10-PCS and is categorized as one of the nine medical and surgical-related procedure sections. Similar to other ICD-10-PCS codes, obstetric procedure codes are seven characters in length with each of the seven characters representing an aspect of the procedure. The diagram above illustrates the seven characters of a code from the obstetrics section.

Obstetric procedure codes have a first character value of “1” and the second character value for body system is pregnancy. There are a total of 12 root operations (third character) in the obstetrics section:

  • Change (2): taking out or off a device from a body part and putting back an identical or similar device in or on the same body part without cutting or puncturing the skin or a mucous membrane
  • Drainage (9): taking or letting out fluids or gases from a body part
  • Abortion (A): artificially terminating a pregnancy
  • Extraction (D): pulling or stripping out or off all or a portion of a body part by the use of force
  • Delivery (E): assisting the passage of the products on conception from the genital canal
  • Insertion (H): putting in a nonbiological appliance that monitors, assists, performs, or prevents a physiological function, but does not physically take the place of a body part
  • Inspection (J): visually or manually exploring a body part
  • Removal (P): taking out or off a device from a body part, region or orifice
  • Repair (Q): restoring, to the extent possible, a body part to its normal anatomic structure and function
  • Reposition (S): moving to its normal location or other suitable location all or a portion of a body part
  • Resection (T): cutting out or off, without replacement, all of a body part
  • Transplantation (Y): putting in or on all or a portion of a living body part taken from another individual or animal to physically take the place or function of all or a portion of a similar body part

The body part values (fourth character) in the obstetrics section are products of conception; products of conception, retained; and products of conception, ectopic.

The fifth character specifies approach (i.e., open, via natural or artificial opening), and the sixth character indicates devices such as fetal-monitoring electrodes. The last character is a qualifier and is specific to a particular root operation. This seventh character is used to specify the type of extraction (e.g., low forceps, low cervical cesarean), the type of fluid taken out during a drainage procedure (e.g., amniotic fluid, fetal blood), or the body system of the products of conception on which the repair was done.

Only procedures performed on the products of conception are included in the obstetrics section. Procedures performed on the pregnant female other than the products of conception are coded to a root operation in the medical and surgical section of ICD-10-PCS.

Examples of procedures performed on the products of conception are manually assisted delivery (10E0XZZ), delivery with mid forceps (10D07Z4), and low cervical cesarean section (10D00Z1). Examples of procedures performed on the pregnant female are repair of vaginal laceration (0UQGXZZ), episiotomy (0W8NXZZ), episiorrhaphy (0WQNXZZ).


Centers for Medicare and Medicaid Services. “2010 ICD-10-PCS.” Available online at www.cms.hhs.gov/ICD10.

National Center for Health Statistics. “ICD-10-CM Official Guidelines for Coding and Reporting.” Available online at www.cdc.gov/nchs/icd/icd10cm.htm.

National Center for Health Statistics. “2010 ICD-10-CM.” Available online at www.cdc.gov/nchs/icd/icd10cm.htm.

Ann Barta (ann.barta@ahima.org) is a professional practice resource specialist at AHIMA.

Article citation:
Barta, Ann. "Obstetric Coding in ICD-10-CM/PCS" Journal of AHIMA 81, no.6 (June 2010): 68-70.