If you have already filed your return you MUST WAIT until the IRS accepts your return.
And, if you are due a refund it is best to wait until you have actually received your refund. Then, and only then you can prepare an amended return and add your spouse. The amended return MUST be PRINTED and MAILED --it CANNOT be e-filed. An amended return generally can take 3-4 months for the IRS to process it --and the processing of amended returns does not start until later in the year.
If your return is rejected, you can add your spouse at the same time as you make the corrections required by the IRS and resubmit your e-file.
Above all, DO NOT DO ANYTHING until your return is accepted or rejected.
When mailing a printed return it is always a good idea to go to the Post Office and mail it 'Certified' with 'Return Receipt'. That way you will have proof that they received it and when it was received.
To start and amended return using the Desktop version of the program look for the 'AMEND' button/link on the first screen you see when you launch TTax.
