If you don't hold a clearance weed usage won't really be a problem. And if you do apply for a clearance, past marijuana usage is not necessarily a disqualifier

If you don't hold a clearance weed usage won't really be a problem. And if you do apply for a clearance, past marijuana usage is not necessarily a disqualifier. What they're screening for is substance abuse that might be problematic enough that they could compromise your ability to keep secrets. And they want to see that you don't lie about past use. I know more than one person who has smoked weed in the past and still gained a clearance. But really I think the absurdly slow and convoluted gov't application/hiring process, lower pay, and paltry starting annual vacation are bigger deterrents to joining government IT.