Yes, you will need to mail the federal and California amended returns. Please make sure that when you mail them, you send them via a service that provides proof of delivery (certified mail with return receipt, USPS Priority or Express mail, UPS, or any carrier that provides tracking).
For the federal amended return:
When you have prepared your amended return and are ready to mail Form 1040-X you should include the following forms:
- Form 1040-X
- The new (amended) Form 1040
- Any forms or schedules that were added or changed as a result of preparing the amendment
The mailing address for you state and situation can be found at https://www.irs.gov/pub/irs-pdf/i1040x.pdf. Look under Where to File on page 14.
California does require that you attach a copy of the federal amended return, so you will need two copies (plus one for your records). The mailing address for your amended California return can be found at https://www.ftb.ca.gov/aboutFTB/add.shtml
