The Additional Service Credit Cost Estimator is provided solely as a tool for you to obtain an unofficial estimate of your cost to purchase additional service credit. This calculator uses only the data you input and does not compare that data against your actual records with this system. The Connecticut Teachers' Retirement Board (CTRB) accepts no responsibility for any errors or defects in the calculator or in any data you may input. The CTRB retains no record of estimates produced by this calculator. Accordingly, no estimate produced by this calculator shall be in any way binding upon the CTRB. The CTRB, governed by Chapter 167a of the Connecticut General Statutes, has sole authority in determining the cost of your additional service credit.