There are several factors that might optimize your monthly retirement benefit.
Your birthday, or immediately following your birthday, or at any three-month
interval after your birthday is a good time to retire because your age is counted in quarter-years for determination of benefits (up to 60 for Miscellaneous members and 50 for safety members).
Cost of Living Increase
Annual cost of living increase, which is effective on April 1st of each year. If you plan to retire in the spring, you might want to choose a date no later than April 1st so that your retirement allowance includes any cost-of-living adjustment (Tier 1 members only).
Selling Any Vacation or Sick Leave
If you are a member and plan to retire within the next year (for Tier I) or next three years (Tiers II, III, and IV) selling any vacation or sick leave during the 25th pay period will increase your final average compensation.