California FTB announced tax year 2017, that Individual California Amended returns can be electronically filed.

Beginning with  tax year 2017, the Franchise Tax Board (FTB) eliminated the Form 540X, Amended Individual Income Tax Return, for amending individual tax returns and replaced it with the 540 series forms, each adapted to allow for amended return filing. At the same time, FTB introduced the new Schedule X, California Explanation of Amended Return Changes, which will reconcile the difference between the original return and amended return to determine any additional amount owed or refund due, and to provide reasons for amending.

Starting January 2018, FTB’s e-file program will begin accepting e-file amended returns for individuals on taxyear 2017 Forms 540, 540NR Long, 540NR Short, and 540 2EZ, as well as, new Schedule X. For tax year 2016 and prior years, amended individual returns will need to continue to be paper filed using Form 540X.

Resources: https://www.ftb.ca.gov/professionals/efile/tutorial/faq.shtml

Solution:

Intuit ProConnect Lacerte supports the e-filing of Individual amended returns for California using the Tax Year 2018 program. Prior to 2018 Lacerte, this form is not supported and must be paper filed.