Each ACERA tier has its own set of age factors. When ACERA uses the retirement formula to calculate your retirement benefit, we use the age factor percentage from your tier for the age your retire at.
Age factor percentages increase with every quarter of your birthday, up to a maximum. If your birthday is on January 15, your next quarter age is three months later on April 15, the quarter after that is three months later on July 15, and the next quarter is on October 15. The older you are when you retire, the higher the age factor (up to the maximum for each tier). Once you reach the maximum age factor percentage for your tier, you will receive the maximum age factor no matter how old you are when you retire.
The chart below for maximum age and factors used at retirement. Farther down the page you’ll find a PDF that has the chart of all the age factors for all ACERA tiers. Which tier you’re in depends on which employer you work for and when you started.