It has likely changed since I last checked before his presidency, but he had a Top Secret Clearance with NO SCI.

I knew he had admitted to actively using drugs a few times and I wondered how he held an active security clearance. What I could find was essentially: SpaceX was the best option for the US government to conduct satellite-based intelligence missions, as in launch satellites into orbit for the purpose of Space Force related surveillance.

To that end they waived a lot of sketchy shit on Elon’s background to give him a TS so he could primarily attend and give briefings, but no SCI as he didn’t actually do any work requiring it.

Source: I wish I could fucking find any now, but there’s a flood of thousands of article talking about his security clearance as a presidential advisor now.