Every year, we have a lot of changes in the coding guidelines. This year also we have a lot of changes in ICD 10 coding guidelines. The updated guidelines have introduced lot of new diagnosis codes. If you are not aware of the new ICD 10 codes, you can read the below post to know more about them.

New ICD 10 Z codes in 2018

New Ulcer diagnosis codes in 2018

List of Updated ICD 10 codes in 2018

New ICD 10 coding guidelines changes for Z3A category in 2018

New Coding guidelines for Z3A category in 2018

Some of the new diagnosis codes will be limited to use as secondary diagnosis. Yes, the Z3A category is not allowed to be coded along with the abortion diagnosis codes i.e. (codes O00-O08).


The code range for use with Z3A, weeks of gestation, has changed from O00-O9A to O09-O9A to reflect the guideline change last year to remove the requirement to use this code with any code that describes pregnancy with an abortive outcome (codes O00-O08).

Below is the actual coding guidelines in 2018 as per codebook

Read also: New CPT code changes in 2018 in Radiology facility

Encounters for Obstetrical and Reproductive Services

See Section I.C.15. Pregnancy, Childbirth, and the Puerperium, for further instruction on the use of these codes.

Z codes for pregnancy are for use in those circumstances when none of the problems or complications included in the codes from the Obstetrics chapter exist (a routine prenatal visit or postpartum care). Codes in category Z34, Encounter for supervision of normal pregnancy, are always first-listed and are not to be used with any other code from the OB chapter.

Codes in category Z3A, Weeks of gestation, may be assigned to provide additional information about the pregnancy. Category Z3A codes should not be assigned for pregnancies with abortive outcomes (categories O00-O08), elective termination of pregnancy (code Z33.2), nor for postpartum conditions, as category Z3A is not applicable to these conditions. The date of the admission should be used to determine weeks of gestation for inpatient admissions that encompass more than one gestational week.