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O31.42X1 ICD-10-CM Code: Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 1

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

Code Set: New for FY2027 — not valid before October 1, 2026.

Official Registry Overview & Definition

No additional overview provided for this record.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for O31.42X1 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.

Frequently Compared Codes

The official Excludes notes on O31.42X1 name these codes. Each comparison page covers when the two can — or must not — be reported together.

Change history

  • FY2027 — 2026-10-01
    Added to the code set
    Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 1
    FY2027 changes

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Contextual Map

Every relationship of O31.42X1 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • O00-O9A — Chapter 15: Pregnancy, Childbirth and the Puerperium (O00-O9A) (O00-O9A) [Hierarchy]
  • O30-O48 — Maternal care related to the fetus and amniotic cavity and possible delivery problems [Hierarchy]
  • O31 — Clinical Diagnosis [Hierarchy]
  • O31.4 — Clinical Diagnosis [Hierarchy]
  • O31.42 — Clinical Diagnosis [Hierarchy]
  • O31.42X — Clinical Diagnosis [Hierarchy]

Nearest codes (40)

  • O31 — Complications specific to multiple gestation [Sibling]
  • O31.33X9 — Continuing pregnancy after elective fetal reduction of one fetus or more, third trimester, other fetus [Sibling]
  • O31.4 — Continuing pregnancy after vanishing twin syndrome of one fetus or more [Sibling]
  • O31.40 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester [Sibling]
  • O31.40X0 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, not applicable or unspecified [Sibling]
  • O31.40X1 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 1 [Sibling]
  • O31.40X2 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 2 [Sibling]
  • O31.40X3 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, unspecified trimester, fetus 3 [Sibling]
  • and 32 more

Change history

  • FY2027 — Added to the code set [Change history]

Frequently Asked Questions (FAQ) & Clinical Guidance

Does O31.42X1 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 O31.42X1 in its code family, with their registry titles.

  • O31.41X4 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester, fetus 4
  • O31.41X5 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester, fetus 5
  • O31.41X9 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, first trimester, other fetus
  • O31.42 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester
  • O31.42X0 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, not applicable or unspecified
  • O31.42X2 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 2
  • O31.42X3 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 3
  • O31.42X4 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 4
  • O31.42X5 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, fetus 5
  • O31.42X9 — Continuing pregnancy after vanishing twin syndrome of one fetus or more, second trimester, other fetus

View all codes in the O31 family