A 529 account owner can always withdraw at any time for any reason, but there may be tax consequences associated with non-qualified withdrawals, just as with a non-superfunded account. In particular, you want to look closely at any state "clawback" provisions that might be associated with an early withdrawal. If it's a qualified withdrawal, however, you're good to go!
VP, Research & Development
This information does not constitute tax advice and is provided for informational purposes only. Please consult your tax advisor, financial advisor, local taxing authority, and/or plan provider or sponsor for more information.