I’ve already filed my federal tax return and the IRS already accepted it, but I forgot to add a 10-99 form to the files because the contratist did not give me the form on time, is there anything

[CatinaT1]

If you filed, it is like dropping it into a mailbox - you cannot get it back.

You'll have wait until your return is either accepted or rejected. 

• If rejected, you can make any necessary changes. 
• If accepted, you'll need to amend your return. 
• To avoid unnecessary delays, do not amend until your original return has been fully processed.  You will need to print and mail the amendment.  
• Allow 8-12 weeks for processing.

See this TurboTax FAQ for help with amending.

You can check the status of your amended return here, but allow 3 weeks after filing for it to show up