See the IRS’s press release. For business expense reimbursement, the 2019 rate is $0.58 per mile. That’s up $0.035 from last year. California employers need to reimburse such common expenses as work-related travel, dining expenses and mileage when an employee uses a personal car for work-related business. However, employees who can prove they spend more than $0.58 per mile to operate their personal vehicles for business use may be entitled to reimbursement of the actual expense. It’s up to the employees to prove their expenses, however.