I've been drug tested by an outside lab prior to employment by an outside lab (not the employer itself). Yes the Concerta will show up in the drug test. A medical review officer will contact you and ask about either the doctor who prescribes the med or the pharmacy you get the med from. They are supposed to contact the doctor or pharmacy. Or they may require you to produce a copy of your prescription, predating your drug test of course. If the required proof is received, then the results are reported as negative to the employer. They cannot reveal the medication you take or the reason you take it, because if they do, they are violating HIPPA laws.