A repayment is a returned payment, a cash refund, or an amount withheld for overpayment purposes.
Under the Internal Revenue Code, the RRB is allowed to give repayment credit for the SSEB and/or pre-SSEB portion of tier I for any tax year. Refer to IRS Publication 915, "Social Security and Equivalent Railroad Retirement Benefits", for information regarding current tax year or prior tax year's SSEB repayment.