Each state sets their own requirements on what the minimum age will be for becoming a police officer and if there will be a maximum age and if so what that will be. Individual agencies may then set their own policies for minimum and maximum age requirements which fall within the limits of the state requirements but may be more restrictive.
The minimum age requirement could be anywhere between 18-21 years of age. Some departments will have a minimum age requirement for applying such as 20, with the requirement that you be 21 when you are sworn in.
The maximum age requirement applies to those applying for new positions with that agency. Often, the maximum age requirement is based upon the amount of time it would take to retire with full benefits and still retire “on time.” Say for example the mandatory retirement age is 57 for a department, so for a police officer to retire with 20 years a new officer must start with that department by age 37. Therefore, the maximum age requirement is 37 years old.
Some departments do not have maximum age requirements. Generally the minimum and maximum age requirements (if any) are posted on the vacancy announcement. Some exceptions to maximum age requirements are available for those with military service. This exception applies to certain federal law enforcement positions.