The time to use 59025 to code a fetal non-stress test is when the patient records that she has felt the baby moving. If not then the fetal monitor is counted as routine. What makes the NST Code True? When you use the code 59025 for the fetal non-stress test for NST procedures you must make sure you are using them correctly. How that happens is that during the NST procedure the ob-gyn evaluates the patient and evaluates the well being of the fetus with out the use of IV medications. The test lasts for approximately 30-40 minutes, and the ob-gyn monitors the heart rate of the fetus using external …