I filed my tax return today. I forgot to add information about the 1099-MISC form in the process. If I need to sen the amendment, do I need to wait until next year?

All 2022 income must be reported on a 2022 return.

You cannot change or add anything on the return that you just e-filed, nor can you stop it.  It is too late, just like when you put an envelope in a US mailbox on the corner.  The IRS does not allow you to take it back.

If you left out a W-2, a 1099G, or a dependent, or a 1099 etc…DO NOT change your return while it is “pending.”  The changes will go nowhere.

Now you have to wait until the IRS either rejects or accepts your return.  If your return is rejected, you will be able to go into your account and make the necessary changes to your tax return and re-submit your return. 

 If the IRS accepts your return, however, then you have to wait longer until it has been fully processed and you have received your refund.  THEN you can prepare an amended tax return and e-file or mail  it in. You have to be able to work from that return exactly the way it was when it was e-filed originally.  You will need to use a form called a 1040X.

  Meanwhile, DO NOT go in and start changing anything on your return in the system, or you will make a mess for yourself.  Sit tight and wait until you see what the IRS does with the return you just e-filed

The Form 1040X you need to use will not be available until late February.

Your pending returns can not be changed. If your return is accepted you will get an email. If the return is rejected the e-mail will tell you what to correct and you can make changes before e-filing again. Amend to change an accepted return after you get your refund. Instructions below. https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-filed/00/25588