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ICD-10-CM 2027 diagnosis code

O24.01Pre-existing type 1 diabetes mellitus, in pregnancy

Not billable — use a more specific code

O24.01 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

Code last changed in FY2017 (effective October 1, 2016). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About O24.01

O24.01 is the ICD-10-CM diagnosis code for pre-existing type 1 diabetes mellitus, in pregnancy. It belongs to category O24 (diabetes mellitus in pregnancy, childbirth, and the puerperium), block O20-O29 (other maternal disorders predominantly related to pregnancy) 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 O24.0 (pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium), O24.01 is specifically for pre-existing type 1 diabetes mellitus, in pregnancy. Related codes cover childbirth (O24.02) and the puerperium (O24.03).

To report this condition, pick the subcode that matches the documentation: O24.011 (first trimester), O24.012 (second trimester), O24.013 (third trimester) and O24.019 (unspecified trimester).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2017 (title revised).

Specific codes under O24.01

Notes that apply from higher levels

Instructions written at a parent level also apply to O24.01.

› From O24.0 Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium
Use additional code
  • code from category E10 to further identify any manifestations

Broader instructions also apply from O20-O29 Other maternal disorders predominantly related to pregnancy and Chapter 15: Pregnancy, childbirth and the puerperium.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to O24.01.

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)
  • FY2017 (effective 10/1/2016): Title revised — was “Pre-existing diabetes mellitus, type 1, in pregnancy”

Common questions about O24.01

Is O24.01 billable?

No. O24.01 is a header code. Report one of its more specific subcodes instead.