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ICD-10-CM 2027 diagnosis code

O41.1024Infection of amniotic sac and membranes, unspecified, second trimester, fetus 4

✓ Billable / specificRequires 7th characterMCC — major complication/comorbidityMaternity · age 9–64Female only

O41.1024 is a valid, billable ICD-10-CM code for infection of amniotic sac and membranes, unspecified, second trimester, fetus 4. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Infct of amniotic sac and membrns, unsp, second tri, fetus 4

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 O41.1024

O41.1024 is the ICD-10-CM diagnosis code for infection of amniotic sac and membranes, unspecified, second trimester, fetus 4. It belongs to category O41 (other disorders of amniotic fluid and membranes), 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 "4" means fetus 4.

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" 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 658.41 (infection of amniotic cavity, delivered, with or without mention of antepartum condition) and 658.43 (infection of amniotic cavity, antepartum condition or complication).

7th character

4fetus 4

Other encounter types for O41.102:

Notes that apply from higher levels

Instructions written at a parent level also apply to O41.1024.

› From O41 Other disorders of amniotic fluid and membranes
Excludes1
  • encounter for suspected maternal and fetal conditions ruled out (Z03.7-)

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 →
  • 658.41Infection of amniotic cavity, delivered, with or without mention of antepartum conditionapproximate
  • 658.43Infection of amniotic cavity, 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 O41.1024

Is O41.1024 billable?

Yes. O41.1024 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "4" at the end of O41.1024 mean?

It is the 7th character for fetus 4.

Can O41.1024 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict O41.1024 as a principal diagnosis.

Is O41.1024 a CC or MCC?

O41.1024 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does O41.1024 group to?

O41.1024 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 O41.1024?

The CMS General Equivalence Mappings map O41.1024 to ICD-9-CM 658.41 and 658.43.