The Age Discrimination in Employment Act (ADEA) and the California Fair Employment and Housing Act forbid employers from discriminating based on an employee’s age. If you are at least 40 years old, you are protected by these laws.
During a time of layoffs, your employer cannot intentionally single you (or a group of people) out for unequal treatment because you 40 years of age or older. However, even a supposedly “neutral” layoff policy can still be illegal if it disproportionately affects persons over 40.