Oth pre-existing diabetes in pregnancy, third trimester

This code signifies a pregnant patient with a pre-existing form of diabetes mellitus, other than Type 1 or Type 2, who is currently in her third trimester. This could include conditions like secondary diabetes due to cystic fibrosis or pancreatectomy, or other specified types of diabetes. The diabetes was present prior to the current pregnancy.

Use this code when documentation clearly indicates a pregnant patient in her third trimester with a pre-existing diabetes type not classified as Type 1 or Type 2. The medical record should specify the type of diabetes and confirm its presence before conception or early in the pregnancy. This code is appropriate for ongoing management of such conditions during the final trimester.

• Always sequence this code as a primary diagnosis when the diabetes is the main reason for the encounter, or as a secondary diagnosis when managing other pregnancy-related conditions.
• Ensure the documentation specifies "pre-existing" and the specific trimester to differentiate from gestational diabetes or diabetes diagnosed in earlier trimesters.
• Do not use this code for Type 1 (O24.0-) or Type 2 (O24.1-) pre-existing diabetes, or for gestational diabetes (O24.4-).