Public Servants Protection and Fairness Act of 2021 This bill establishes an alternative formula to calculate Social Security retirement benefits for those who receive pensions for certain non-covered employment. (The existing formula is known as the windfall elimination provision.) The alternative formula adjusts an individual's total lifetime earnings based on the proportion of covered earnings (i.e., earnings subject to Social Security payroll taxes). It applies to individuals who (1) first become eligible for benefits after 2022, (2) have earnings from non-covered service performed after 1977, and (3) have less than 30 years of coverage (i.e., years in which a beneficiary is considered to have contributed a substantial amount into the Social Security trust funds). Beneficiaries receive the higher benefit amount as calculated under the alternative method or the existing formula. In addition, the bill provides rebates for certain beneficiaries currently impacted by the existing formula. The Social Security Administration must include non-covered earnings in Social Security account statements, and the Government Accountability Office must study the availability of certain information related to retirement plans maintained by state and local governments.