FY2027 ICD-10-CM reference
O31.31X2: Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 2
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 2. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
Source: O00-O9A (chapter, inherited).
Instructional note
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)
Source: O00-O9A (chapter, inherited).
Instructional note
Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
Source: O00-O9A (chapter, inherited).
Instructional note
1st trimester- less than 14 weeks 0 days
Source: O00-O9A (chapter, inherited).
Instructional note
2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
Source: O00-O9A (chapter, inherited).
Instructional note
3rd trimester- 28 weeks 0 days until delivery
Source: O00-O9A (chapter, inherited).
Instructional note
code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Source: O00-O9A (chapter, inherited).
Excludes1
supervision of normal pregnancy (Z34.-)
Source: O00-O9A (chapter, inherited).
Excludes2
mental and behavioral disorders associated with the puerperium (F53.-)
Source: O00-O9A (chapter, inherited).
Excludes2
obstetrical tetanus (A34)
Source: O00-O9A (chapter, inherited).
Excludes2
postpartum necrosis of pituitary gland (E23.0)
Source: O00-O9A (chapter, inherited).
Excludes2
puerperal osteomalacia (M83.0)
Source: O00-O9A (chapter, inherited).
Excludes2
delayed delivery of second twin, triplet, etc. (O63.2)
Source: O31 (category, inherited).
Excludes2
malpresentation of one fetus or more (O32.9)
Source: O31 (category, inherited).
Excludes2
placental transfusion syndromes (O43.0-)
Source: O31 (category, inherited).
Seventh-character instruction
One of the following 7th characters is to be assigned to each code under category O31. 7th character 0 is for single gestations and multiple gestations where the fetus is unspecified. 7th 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 category O31 that has a 7th character of 1 through 9.
Source: O31 (category, inherited).
Instructional note
not applicable or unspecified
Source: O31 (category, inherited).
Instructional note
fetus 1
Source: O31 (category, inherited).
Instructional note
fetus 2
Source: O31 (category, inherited).
Instructional note
fetus 3
Source: O31 (category, inherited).
Instructional note
fetus 4
Source: O31 (category, inherited).
Instructional note
fetus 5
Source: O31 (category, inherited).
Instructional note
other fetus
Source: O31 (category, inherited).
Instructional note
Continuing pregnancy after selective termination of one fetus or more
Source: O31.3 (self, inherited).
Seventh-character definitions
- 0: not applicable or unspecified
- 1: fetus 1
- 2: fetus 2
- 3: fetus 3
- 4: fetus 4
- 5: fetus 5
- 9: other fetus
Compare the FY2027 additions, removals and billable-status changes
What does O31.31X2 mean in FY2027?
The official ICD-10-CM descriptor is Continuing pregnancy after elective fetal reduction of one fetus or more, first trimester, fetus 2. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is O31.31X2 billable in FY2027?
The FY2027 order file marks O31.31X2 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does O31.31X2 map to an HCC?
O31.31X2 has no CMS-HCC V28 category in the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service). Under the PY2026 CMS mapping; CMS 2027 initial file unchanged: no ESRD category; no RxHCC category. Coefficients for these models are pending verification for payment year 2027. HHS-HCC: HCC 210 (This code has a CMS age requirement: applies when 9 <= age <= 64) under the HHS-HCC 2026 benefit year mapping (no RAF; HHS-HCC weights vary by metal level). CMS-HCC V24: not used for payment year 2027 Medicare Advantage payment (CMS CY 2027 Rate Announcement). The PACE mapping is still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition