Can a Canadian citizen, living and working in the U.S. establish IRA/Roth IRA/401k accounts? If so, where is the rule or IRS publication?

Would the person have a *valid* American Social Security Number? It is also called a tax identification number or TIN.

No TIN, no account.

Would the person have a *valid* American Social Security Number? It is aslo called a tax identification number or TIN.

No TIN, no account.
This person has a SSN, but I did not know non-US citizens could get a SSN. IRS form 519 talks about Resident Aliens having the same rights to IRAs as US citizens, but there seems to be a lot of gray area.

When I did extensive work selling IRA's and processing them, the only requirement was a *valid* SSN. There was no requirement to see birth certificates. This was a few years back, so I guess I'm not up to date in tax code changes.