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ICD-10-CM 2027 diagnosis code

O31.43X0Continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester, not applicable or unspecified

✓ Billable / specificNew for 2027Requires 7th characterMaternity · age 9–64

O31.43X0 is a valid, billable ICD-10-CM code for continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester, not applicable or unspecified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Cont preg aft vanishing twin syn 1 fts or more,3rd tri,unsp

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 O31.43X0

O31.43X0 is the ICD-10-CM diagnosis code for Continuing pregnancy after vanishing twin syndrome of one fetus or more, third trimester, not applicable or unspecified. 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 billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "0" means not applicable or unspecified.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 817 (Other Antepartum Diagnoses with O.R. Procedures with MCC, relative weight 2.0534), DRG 818 (Other Antepartum Diagnoses with O.R. Procedures with CC, relative weight 1.2942), DRG 819 (Other Antepartum Diagnoses with O.R. Procedures without CC/MCC, relative weight 0.7739), DRG 831 (Other Antepartum Diagnoses without O.R. Procedures with MCC, relative weight 1.1558), DRG 832 (Other Antepartum Diagnoses without O.R. Procedures with CC, relative weight 0.7585) and DRG 833 (Other Antepartum Diagnoses without O.R. Procedures without CC/MCC, relative weight 0.5002), in MDC 14 (Pregnancy, Childbirth and the Puerperium), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor treats this as a maternity diagnosis, expected only for patients age 9 through 64.

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

7th character

0not applicable or unspecified

Other encounter types for O31.43:

Notes that apply from higher levels

Instructions written at a parent level also apply to O31.43X0.

› 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.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

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 O31.43X0

Is O31.43X0 billable?

Yes. O31.43X0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "0" at the end of O31.43X0 mean?

It is the 7th character for not applicable or unspecified.

Can O31.43X0 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O31.43X0 as a principal diagnosis.

Is O31.43X0 a CC or MCC?

No. O31.43X0 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does O31.43X0 group to?

O31.43X0 is used in the MS-DRG v44.0 logic for MS-DRG 817 (Other Antepartum Diagnoses with O.R. Procedures with MCC), MS-DRG 818 (Other Antepartum Diagnoses with O.R. Procedures with CC), MS-DRG 819 (Other Antepartum Diagnoses with O.R. Procedures without CC/MCC), MS-DRG 831 (Other Antepartum Diagnoses without O.R. Procedures with MCC), MS-DRG 832 (Other Antepartum Diagnoses without O.R. Procedures with CC) and MS-DRG 833 (Other Antepartum Diagnoses without O.R. Procedures without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

Did O31.43X0 change for 2027?

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