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ICD-10-CM 2027 diagnosis code

O31.21X0Continuing pregnancy after intrauterine death of one fetus or more, first trimester, not applicable or unspecified

✓ Billable / specificRequires 7th characterMaternity · age 9–64Female only

O31.21X0 is a valid, billable ICD-10-CM code for continuing pregnancy after intrauterine death of one fetus or more, first 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 uterin dth of one fts or more, first tri, unsp

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O31.21X0

O31.21X0 is the ICD-10-CM diagnosis code for Continuing pregnancy after intrauterine death of one fetus or more, first 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 is on the CMS list of diagnoses consistent only with female patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 651.31 (twin pregnancy with fetal loss and retention of one fetus, delivered, with or without mention of antepartum condition), 651.33 (twin pregnancy with fetal loss and retention of one fetus, antepartum condition or complication), 651.61 (other multiple pregnancy with fetal loss and retention of one or more fetus(es), delivered, with or without mention of antepartum condition) and 1 more.

7th character

0not applicable or unspecified

Other encounter types for O31.21:

Notes that apply from higher levels

Instructions written at a parent level also apply to O31.21X0.

› 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.

ICD-9-CM equivalent

Converter →
  • 651.31Twin pregnancy with fetal loss and retention of one fetus, delivered, with or without mention of antepartum conditionapproximate
  • 651.33Twin pregnancy with fetal loss and retention of one fetus, antepartum condition or complicationapproximate
  • 651.61Other multiple pregnancy with fetal loss and retention of one or more fetus(es), delivered, with or without mention of antepartum conditionapproximate
  • 651.63Other multiple pregnancy with fetal loss and retention of one or more fetus(es), antepartum condition or complicationapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

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
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about O31.21X0

Is O31.21X0 billable?

Yes. O31.21X0 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 O31.21X0 mean?

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

Can O31.21X0 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O31.21X0 as a principal diagnosis.

Is O31.21X0 a CC or MCC?

No. O31.21X0 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does O31.21X0 group to?

O31.21X0 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.

What is the ICD-9 code for O31.21X0?

The CMS General Equivalence Mappings map O31.21X0 to ICD-9-CM 651.31, 651.33, 651.61 and 651.63.