Cálix William

WILLIAM CÁLIX focuses his practice on all aspects of corporate restructuring, including bankruptcy court proceedings and representing debtors, creditors, and investors in large and complex restructuring transactions.

Prior to joining Sidley, William served as a legal intern for Disability Rights DC’s Jail and Prison Advocacy Project in Washington, D.C., navigating the prison system and working to improve the treatment of incarcerated people.

While attending Georgetown University Law Center, William served as managing editor for the Georgetown Immigration Law Journal and as a competing member of the Barristers’ Council Trial Advocacy Team.

William is fluent in Spanish.

Debtor/Company - Side Experience

• Prospect Medical Holdings, Inc. (Prospect) and several of its subsidiaries in its Chapter 11 cases in the United States Bankruptcy Court for the Northern District of Texas. With over US$2.3 billion in outstanding funded debt, Prospect’s Chapter 11 cases are among the largest filed in 2025.
• Telecommunications hardware and software company, Casa Systems, Inc., and certain of its affiliates, in their Chapter 11 proceedings in the Bankruptcy Court for the District of Delaware.

Additional Representations

• Cummins Inc. in its stalking horse bid to purchase substantially all of the assets of First Mode Holdings and certain of its affiliates through a Chapter 11 sale under section 363 of the U.S. Bankruptcy Code.