I have made 2 harship withdrawals to pay for my son's education expensens in the past 6 months and both times I wasn't asked to submit the proof (even though it initially says to have some before I make the reqeust). Do they come back later to ask for it? If they do how much later? I just want to know if I need to save the proof of the expenses and for how long? My 401K is throuh Fidelity.
Yes, I'd keep the supporting documentation along with any other receipts, bank statements, etc. you'd need to support filing your taxes.
It's an IRS issue, I don't think Fidelity cares. Strongly recommend starting your taxes very early this year. If there's some paperwork you need to get, April 13th would be a very bad day to find out. And like all other tax stuff, you should keep it for a minimum of 7 years.
I have my son's 529 with Fidelity. Although this isn't a 401K, whenever I've called in to request withdrawals to pay his tuition, they simply ask the reason for the distribution. To date, Fidelity hasn't asked for any documentation.