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.
1 B vitamins such as folic acid, vitamin B12, and vitamin B6 help the body maintain homocysteine levels within a healthy range.  Up to half of Americans carry a genetic variation that is linked with elevated homocysteine levels.