If you already filed and the return was accepted
by IRS, you have to wait until you receive your refund before you
can amend your taxes to add the new 1098. You can amend your taxes any time this
year.
If your return is rejected or
not yet submitted, you
can edit any time by adding the additional information.
See this TurboTax support FAQ for amending a tax
return
https://ttlc.intuit.com/replies/3288565
