I searched the forums, and found a lot on purchasing a firearm while being a MMJ cardholder, but didn't really find much specifically talking about mmj + ccw.

I have a friend who wants to take the ccw class with me, but before he signs up, he aked me if I knew whether having his mmj card will prevent him from lawfully being able to conceal? I didn't have an answer for him, so I told him I'll ask around and get back to him.