Kansas Bankers Surety Company (KBS) is an insurance company based in the United States. It is a wholly owned subsidiary of Berkshire Hathaway, the investment vehicle of Warren Buffett. It specializes in the writing of surety bonds for the officers of small, state chartered banks in the Midwestern United States. It formerly also wrote deposit insurance at such banks for coverage in excess of the per-depositor limits of the Federal Deposit Insurance Corporation, but this line of business was discontinued in 2008.