Convert ICD-10 Code O16.1 to ICD-9

Source ICD-10 Code		Target ICD-9 Code
O16.1 Unspecified maternal hypertension, first trimester		642.91 Hypertens NOS-delivered
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.
O16.1 Unspecified maternal hypertension, first trimester		642.93 Hypertens NOS-antepartum
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.
O16.1 Unspecified maternal hypertension, first trimester		642.94 Hypertens NOS-postpartum
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

ICD-10 to ICD-9 crosswalk for code O16.1 - unspecified maternal hypertension, first trimester based on the most recent General Equivalence Mappings (GEMS) information.