For the federal workers that do not know how their retirement annuity is calculated, they are based on your high-3s. Your high-3s are the three highest averages from back-to-back years of your base salary.
The base salary is the amount you make and of which your retirement withholdings are made from.
The base pay is the rate that is set by laws or regulations for your federal post.
For GS workers, your base pay can be comprised of within-grade increases, special pay rates set due to recruitment or due to retainment, locality pay, and certain types of premium pay that typically involves law endowment officers and firefighters.
For those under the wage system, the basic pay also includes environment differential pay.
On the flip side, some items are not considered in your base pay, such as military pay, holiday pay, allowances, bonuses, and overtime. Other items not included are differentials from being in a foreign post, non-foreign area differentials and allowances, and any money made from credit hours under a compressed work schedule.
You can also study your pay stubs to see what kind of deductions are being made aside from the pay assigned for by our locality, grade, and step. You can also check with payroll to see what types of pay are not being considered within your base pay.