O24.011 Pre-existing type 1 diabetes mellitus, in pregnancy, first trimester

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from O24.0 Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium

Applicable to

• Juvenile onset diabetes mellitus, in pregnancy, childbirth and the puerperium
• Ketosis-prone diabetes mellitus in pregnancy, childbirth and the puerperium

Use additional code

• code from category E10 to further identify any manifestations

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 648.01 Diabetes mellitus of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition (approximate)
• 648.03 Diabetes mellitus of mother, complicating pregnancy, childbirth, or the puerperium, antepartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O24.011

Back-references to O24

• Type 2 Excludes: O99.2 Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperium ("diabetes mellitus (O24.-)")
• Type 1 Excludes: R73 Elevated blood glucose level ("diabetes mellitus in pregnancy, childbirth and the puerperium (O24.-)")

Nearby codes

• O24 Diabetes mellitus in pregnancy, childbirth, and the puerperium
• O24.0 Pre-existing type 1 diabetes mellitus, in pregnancy, childbirth and the puerperium
• O24.01 Pre-existing type 1 diabetes mellitus, in pregnancy
• O24.011 Pre-existing type 1 diabetes mellitus, in pregnancy, first trimester (this code)
• O24.012 Pre-existing type 1 diabetes mellitus, in pregnancy, second trimester
• O24.013 Pre-existing type 1 diabetes mellitus, in pregnancy, third trimester
• O24.019 Pre-existing type 1 diabetes mellitus, in pregnancy, unspecified trimester
• O24.02 Pre-existing type 1 diabetes mellitus, in childbirth
• O24.03 Pre-existing type 1 diabetes mellitus, in the puerperium