O26.4Non-Billable (Header)Herpes gestationisChild CodesO26.40Herpes gestationis, unspecified trimesterO26.41Herpes gestationis, first trimesterO26.42Herpes gestationis, second trimesterO26.43Herpes gestationis, third trimesterCode Hierarchy└O26Maternal care for other conditions predominantly related to pregnancy└O26.4Herpes gestationis└O26.4Herpes gestationis