Chapter 11 of the United States Bankruptcy Code (Title 11 of the United States Code) permits reorganization under the bankruptcy laws of the United States. Such reorganization, known as "Chapter 11 bankruptcy", is available to every business, whether organized as a corporation, partnership or sole proprietorship, and to individuals, although it is most prominently used by corporate entities. In contrast, Chapter 7 governs the process of a liquidation bankruptcy, though liquidation may also occur under Chapter 11; while Chapter 13 provides a reorganization process for the majority of private individuals.

Lehman Brothers Holdings Inc. () was a global financial services firm founded in 1847. Before filing for bankruptcy in 2008, Lehman was the fourth-largest investment bank in the United States (behind Goldman Sachs, Morgan Stanley, and Merrill Lynch), with about 25,000 employees worldwide. It was doing business in investment banking, equity and fixed-income sales and trading (especially U.S. Treasury securities), research, investment management, private equity, and private banking. Lehman was operational for 158 years from its founding in 1850 until 2008.On September 15, 2008, the firm filed for Chapter 11 bankruptcy protection following the exodus of most of its clients, drastic losses in its stock, and devaluation of assets by credit rating agencies, largely sparked by a loss of confidence, Lehman's involvement in the subprime mortgage crisis, and its exposure to less liquid assets. Lehman's bankruptcy filing was the largest in US history, and is thought to have played a major role in the unfolding of the financial crisis of 2007–2008. The market collapse also gave support to the "Too big to fail" doctrine.After Lehman Brothers filed for bankruptcy, global markets immediately plummeted. The following day, Barclays announced its agreement to purchase, subject to regulatory approval, Lehman's North American investment-banking and trading divisions along with its New York headquarters building. On September 20, 2008, a revised version of that agreement was approved by U.S. Bankruptcy Court Judge James M. Peck. The next week, Nomura Holdings announced that it would acquire Lehman Brothers' franchise in the Asia-Pacific region, including Japan, Hong Kong and Australia, as well as Lehman Brothers' investment banking and equities businesses in Europe and the Middle East. The deal became effective on October 13, 2008.