Do you mean you received another W-2 or 1099 after you filed or did you try to do one document at a time?
Click here for instructions on how to Amend Your Return.
If you did just one document at a time, be aware that ALL income from ALL sources should be reported on one return. After you enter one document (ex. 1099, W-2, etc) all you need to do is click Add a (name of document) and you will be able to include them all on one return.
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