(a)
Gross income shall not include any amount received by an employee from an employer to compensate for the additional federal income tax liability incurred by the employee because, for federal income tax purposes, the same-sex spouse or domestic partner of the employee is not considered the spouse of the employee under Section 105(a) or Section 106(a) of the Internal Revenue Code, including any compensation for the additional federal income tax liability incurred with respect to those amounts.(b)
This section shall remain in effect only until January 1, 2019, and as of that date is repealed.
Source:
Section 17141.3, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC§ionNum=17141.3..