Modifier 25 should be appended to the office or other. outpatient service code to indicate that a significant, separately. identifiable E/M service was provided by the same physician. on the same day as the preventive medicine service.
The level of homocysteine in the blood can be measured with a simple blood test that is often, but not always, done after fasting. Homocysteine levels of 12 mmol/L are considered normal and levels below 10 mmol/L are considered desirable.
There's evidence that in some people, the accumulation of homocysteine may be caused by a genetic defect, but in others it's simply the result of a vitamin B12 deficiency (although shortages of folate and vitamin B6 can do the same).