Except for a few small exceptions.
Way back in 2014, the U.S. Department of Transportation issued a regulation stating all new cars sold in the country must have a backup camera installed as a standard feature. While most well-optioned cars have come with a standard backup camera for years, there were still a few manufacturers that greedily charged extra while they still could. BMW didn't stop charging for backup cameras until the 2018 model year, and before this regulation kicked in fully, there were still a handful of cheaper models sold without a backup camera.
As of Tuesday, May 1st, 2018, all new passenger cars sold in the U.S. will be legally required to have a backup camera. So, you may think that all 2018 model year cars will have this feature as standard, but not necessarily. Since the regulation didn't take effect unit May 1st, some 2018 model year cars build before this date can be sold without a backup camera. This explains why our 2018 Mazda MX-5 test car came in for a review without sporting a backup camera. If you do go in to buy a new car in 2018, there may still be a handful of 2018 model year and leftover 2017 model year cars on the lot that won't come with a backup camera.
According to the Insurance Institute for Highway Safety, backup cameras have reduced backup-related crashed by 17%. This is a significant figure considering 12,000 people are injured every year in backup incidences, and 200 are killed. Fortunately, if you buy a car after this year, it will definitely come with a backup camera.