Effective January 1, 2017, California Vehicle Code Section 23123.5 has made it illegal to hold and operate a handheld electronic wireless communications device, such as a cell phone, while behind the wheel. 

Across the country, many states have implemented bans on phones and texting:

• Fifteen states, including California, ban the use of handheld phones while driving
• Forty-eight states, including California, ban text messaging while driving
• Thirty-nine states, including California, ban any cell phone use by novice drivers
• Twenty states, including California, prohibit any cell phone use by school bus drivers
• Penalties are getting more severe for cell phone use while driving: seven states impose points on driving records for violating cell phone laws

State Laws: 

• GHSA.org has a current listing of laws for each state
  
• Electronic Wireless Communications Device: Prohibited Use (California Motor Vehicle Code 23123.5)
  
• School Bus or Transit Vehicle Drivers: Prohibition Against Use of Wireless Telephone (California Motor Vehicle Code 23125)
• NHTSA Distracted Driving Overview