ICD-10-CM > O00-O9A > O09-O09 > O09 > O09.5 > O09.51 O09.51 Supervision of elderly primigravida Non-Billable/Non-Specific Codes O09.511Supervision of elderly primigravida, first trimesterO09.512Supervision of elderly primigravida, second trimesterO09.513Supervision of elderly primigravida, third trimesterO09.519Supervision of elderly primigravida, unspecified trimester