It makes no difference how long you've been with a company so yes, it's legal to lay off any and everyone without severance. The exceptions: a union agreement requiring severance, a personal contract calling for a severance. This is usually only for executives and ``key'' people.
Firing in Arizona Firing can occur due to poor performance, misconduct, or a violation of company policies. Arizona follows the “at-will” employment doctrine, allowing employers to terminate employees without cause as long as the termination is not discriminatory or retaliatory.