Firing workers in order to prevent them from earning their promised pensions is a technique some employers use to save money, but it is not legal. When the Older Workers Benefit Protection Act (OWBPA) was passed in 1990, it became clearly illegal for employers: To use an employee's age as the basis for discrimination in benefits, and To target older workers for their staff cutting programs on the basis that benefits were too costly. An employer cannot terminate an older worker on the basis that benefits are too costly. The company must follow the "equal benefits or equal cost" rule, by providing either equal benefits to older and younger workers, or paying the same benefit costs for all employees. The law only allows an employer to reduce benefits based on age only if the cost of providing the reduced benefits to older workers is the same as the cost of providing benefits to younger workers. In other words, if an employer pays only $100 in monthly premiums for each worker, this policy does not violate the ADEA even if it causes the older worker to make a higher employee contribution or to have lesser benefits than a younger worker. An employer could not, however, refuse to pay for the health benefits of all workers over 55 on the grounds that "it costs too much," if the employer pays the benefits of younger workers, or terminates all older workers so that the pool of employees for insurance purposes is less costly to insure.