Ob-Gyn Coding Alert

Question: At the initial ob visit, my ob-gyn does a hemoglobin A1C on all of our patients. If the test results come back elevated, what diagnosis code should I use for the early glucose testing?

California Subscriber

Answer: First of all, you are doing a screening test, and per ICD-9 guidelines, your primary diagnosis is screening:

• V28.89 (Other specified antenatal screening) because this test is part of your antenatal screening tests
• V77.1 (Screening for diabetes mellitus) because your ob-gyn is testing for DM

ICD-10: When your diagnosis system changes in 2013, V28.89 will become Z36 (Encounter for antenatal screening of mother) and V77.1 will become Z13.1 (Encounter for screening for diabetes mellitus).

If the results come back elevated (which you won't knowuntil a few days after the patient underwent the actual test), you code the result.

For instance, if the A1C is less than 6.5% and a fasting glucose is between 96-126, you can then call this gestational diabetes (which may be the case if the patient's previous pregnancy involved gestational diabetes). On the other hand, the ob-gyn might simply consider her high risk for developing diabetes. In that case, you would assign a V23 code (Supervision of high risk pregnancy) with 790.29 (Other abnormal glucose).

ICD-10: When your diagnosis system changes in 2013, V23 will become the O09 (Supervision of high risk pregnancy) category, and 790.29 will become R73.09 (Other abnormal glucose)

But if the test results specify elevations greater than 6.5%, the ob-gyn would say she has overt diabetes. For this condition, you would assign code 648.03 (Antepartum diabetes mellitus).

ICD-10: Code 648.03 will expand into three options, based on trimester: O24.911 (Unspecified diabetes mellitus in pregnancy, first trimester), O24.912 (... second trimester), and O24.913 (... third trimester).

Bottom line: You will need to work with your provider on this issue.