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ICD-10-CM 2027 diagnosis code

O98.91Unspecified maternal infectious and parasitic disease complicating pregnancy

Not billable — use a more specific code

O98.91 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.Short description: Unsp maternal infec/parastc disease complicating pregnancy

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 O98.91

O98.91 is the ICD-10-CM diagnosis code for unspecified maternal infectious and parasitic disease complicating pregnancy. It belongs to category O98 (maternal infectious and parasitic diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium), block O94-O9A (other obstetric conditions, not elsewhere classified) and chapter 15 (pregnancy, childbirth and the puerperium). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within O98.9 (unspecified maternal infectious and parasitic disease complicating pregnancy, childbirth and the puerperium), O98.91 is specifically for unspecified maternal infectious and parasitic disease complicating pregnancy. Related codes cover childbirth (O98.92) and the puerperium (O98.93).

To report this condition, pick the subcode that matches the documentation: O98.911 (first trimester), O98.912 (second trimester), O98.913 (third trimester) and O98.919 (unspecified trimester).

Use an additional code (Chapter 1), to identify specific infectious or parasitic disease.

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

Specific codes under O98.91

Notes that apply from higher levels

Instructions written at a parent level also apply to O98.91.

› From O98 Maternal infectious and parasitic diseases classifiable elsewhere but complicating pregnancy, childbirth and the puerperium
Includes
  • the listed conditions when complicating the pregnant state, when aggravated by the pregnancy, or as a reason for obstetric care
Excludes2
  • herpes gestationis (O26.4-)
  • infectious carrier state (O99.82-, O99.83-)
  • obstetrical tetanus (A34)
  • puerperal infection (O86.-)
  • puerperal sepsis (O85)
  • when the reason for maternal care is that the disease is known or suspected to have affected the fetus (O35-O36)
Use additional code
  • code (Chapter 1), to identify specific infectious or parasitic disease

Broader instructions also apply from Chapter 15: Pregnancy, childbirth and the puerperium.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to O98.91.

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 O98.91

Is O98.91 billable?

No. O98.91 is a header code. Report one of its more specific subcodes instead.