CFSB Bancorp, Inc. operates as a holding company for Colonial Federal Savings Bank that provides various financial services to individuals and small businesses. It accepts various deposits, including non-interest-bearing checking accounts, interest-bearing checking accounts, money market accounts, savings accounts, and certificates of deposit. The company offers one- to four-family residential real estate loans, multi-family real estate loans, commercial real estate loans, second mortgage loans, home equity lines of credit, and consumer loans. In addition, it invests in various investment grade investment securities and liquid assets, including the U.S. treasury obligations, securities of various government-sponsored enterprises, corporate debt, mortgage-backed securities, collateralized mortgage obligations, asset-backed securities, municipal obligations, mutual funds, and certificates of deposit of federally insured institutions. Further, it offers online banking services. The company was founded in 1889 and is based in Quincy, Massachusetts. CFSB Bancorp, Inc. is a subsidiary of 15 Beach, MHC.