O10Pre-existing hypertension complicating pregnancy, childbirth and the puerperium

O10 is the ICD-10-CM diagnosis code for pre-existing hypertension complicating pregnancy, childbirth and the puerperium. It belongs to block O10-O16 (edema, proteinuria and hypertensive disorders in pregnancy, childbirth and the puerperium) and chapter 15 (pregnancy, childbirth and the puerperium). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: O10.0 (puerperium), O10.1 (puerperium), O10.2 (puerperium), O10.3 (puerperium), O10.4 (puerperium) and O10.9 (puerperium).

The conditions in its Excludes2 note aren't part of O10, but may be coded alongside it if the patient has both: pre-existing hypertension with superimposed pre-eclampsia complicating pregnancy, childbirth and the puerperium (O11.-).

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