You should not wait for a notice, and instead amend when the forms are available. If you are expecting a refund, you should wait until you've received the refund. Then, you can amend as soon as the federal amended tax return form 1040-X is available for filing in TurboTax. Use this tool to check availability of forms, including 1040X: Tax form availability
Here is some more information on filing amendments: How to File an Amended Tax Return with the IRS
