ICD-10-CM 2027 diagnosis code
O30.121Triplet pregnancy with two or more monoamniotic fetuses, first trimester
O30.121 is a valid, billable ICD-10-CM code for triplet pregnancy with two or more monoamniotic fetuses, first trimester. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Triplet preg w two or more monoamnio fetuses, first tri
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 O30.121
O30.121 is the ICD-10-CM diagnosis code for triplet pregnancy with two or more monoamniotic fetuses, first trimester. It belongs to category O30 (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.
Within O30.12 (triplet pregnancy with two or more monoamniotic fetuses), O30.121 is specifically for triplet pregnancy with two or more monoamniotic fetuses, first trimester. Related codes cover second trimester (O30.122), third trimester (O30.123) and unspecified trimester (O30.129).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
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 651.11 (triplet pregnancy, delivered, with or without mention of antepartum condition), 651.13 (triplet pregnancy, antepartum condition or complication) and V91.12 (triplet gestation, with two or more monoamniotic fetuses).
Notes that apply from higher levels
Instructions written at a parent level also apply to O30.121.
› From O30 Multiple gestation
- any complications specific to multiple gestation
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.
MDC 14 · Pregnancy, Childbirth and the Puerperium
ICD-9-CM equivalent
Converter →- 651.11Triplet pregnancy, delivered, with or without mention of antepartum conditionapproximate, combination
- 651.13Triplet pregnancy, antepartum condition or complicationapproximate, combination
- V91.12Triplet gestation, with two or more monoamniotic fetusesapproximate, combination
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about O30.121
Is O30.121 billable?
- Yes. O30.121 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can O30.121 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict O30.121 as a principal diagnosis.
Is O30.121 a CC or MCC?
- O30.121 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does O30.121 group to?
- O30.121 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.