Which factor does NOT influence the monthly income benefit received from Social Security Retirement benefits?

The monthly income benefit received from Social Security Retirement benefits is determined by several factors, and one of these is not relevant: sex. The Social Security Administration calculates benefits primarily based on the individual's work history, which includes the number of years worked and the earnings during those years. Additionally, the age at which an individual chooses to retire can significantly affect monthly benefits, with early retirement resulting in reduced benefits and delayed retirement leading to increased benefits.

Income level also plays a critical role, as Social Security formulas consider an individual's average indexed monthly earnings (AIME) calculated over their highest-earning years. However, sex does not influence the amount of benefits an individual receives. The Social Security system is designed to provide equal benefits regardless of the retiree's gender, making it the factor that does not affect the calculation of monthly income benefits.