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ICD-10-CM 2027 diagnosis code

O31.40Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester

Not billable — use a more specific codeNew for 2027Requires 7th character

O31.40 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it and add the required 7th character.Short description: Cont preg aft vanishing twin syn one fts or more, unsp tri

Code last changed in FY2027 (effective October 1, 2026). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O31.40

O31.40 is the ICD-10-CM diagnosis code for Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester. It belongs to category O31 (complications specific to multiple gestation), block O30-O48 (maternal care related to the fetus and amniotic cavity and possible delivery problems) and chapter 15 (pregnancy, childbirth and the puerperium). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.

Within O31.4, choose O31.40 (unspecified trimester) only when documentation doesn't support a more specific option: first trimester (O31.41), second trimester (O31.42) and third trimester (O31.43).

Codes in this range require a 7th character: 0 for not applicable or unspecified, 1 for fetus 1, 2 for fetus 2, 3 for fetus 3, 4 for fetus 4, 5 for fetus 5 and 1 more. Use placeholder "X" characters to fill any empty positions before the 7th character.

It was added in FY2027, effective October 1, 2026.

7th character

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.

Notes that apply from higher levels

Instructions written at a parent level also apply to O31.40.

› From O31 Complications specific to multiple gestation
Excludes2
  • delayed delivery of second twin, triplet, etc. (O63.2)
  • malpresentation of one fetus or more (O32.9)
  • placental transfusion syndromes (O43.0-)

Broader instructions also apply from Chapter 15: Pregnancy, childbirth and the puerperium.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2027 (effective 10/1/2026): Added

Common questions about O31.40

Is O31.40 billable?

No. O31.40 is a header code. Report one of its more specific subcodes instead.

Did O31.40 change for 2027?

Yes. For FY2027 (effective October 1, 2026) it was added to the code set.