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ICD-10/O31.33X4

O31.33X4 ICD-10-CM Code: Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 4

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0 (FY2026), Appendix B.

  • MS-DRG 817 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 818 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 819 — OTHER ANTEPARTUM DIAGNOSES WITH O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)
  • MS-DRG 831 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH MCC (MDC 14)
  • MS-DRG 832 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITH CC (MDC 14)
  • MS-DRG 833 — OTHER ANTEPARTUM DIAGNOSES WITHOUT O.R. PROCEDURES WITHOUT CC/MCC (MDC 14)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 4 is a billable ICD-10-CM diagnosis code (O31.334).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for O31.33X4 in the official ICD-10-CM tabular list.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • delayed delivery of second twin, triplet, etc. (O63.2)
  • malpresentation of one fetus or more (O32.9)
  • placental transfusion syndromes (O43.0-)

Frequently Asked Questions (FAQ) & Clinical Guidance

Does O31.33X4 require a 7th character?

Yes. 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..

Nearest Codes in This Family

Official ICD-10-CM classifications closest to O31.33X4 in its code family, with their registry titles.

  • O31.33 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester
  • O31.33X0 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, not applicable or unspecified
  • O31.33X1 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 1
  • O31.33X2 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 2
  • O31.33X3 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 3
  • O31.33X5 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, fetus 5
  • O31.33X9 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, other fetus
  • O31.4 — Continuing pregnancy after vanishing twin syndrome of one fetus or more
  • O31.40 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester
  • O31.40X0 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, not applicable or unspecified

View all codes in the O31 family