Even though money is one of the primary mechanisms managers use for motivating people in the workplace, why wouldn't money be treated as a higher-order factor on any of the four theories of motivation?

Generally, money sits with lower-level needs: safety and physiological for Maslow's hierarchy of needs, existence for Alderfer's ERG theory, and hygiene factors for Hertzberg's two-factor theory. Money provides us with food, housing, clothing, and all the necessities of life. Most people who live in modern societies and work in contemporary organizations receive a paycheck that affords them a certain standard of living. This means their lower-level needs are already being satisfied. Instead, the theories state that people focus on higher-level needs, such as belongingness, esteem, and self-actualization according to Maslow, relatedness and growth for Alderfer, and Hertzberg's motivator factors. Money is not as important here according to these theorists.