California Code, Code of Civil Procedure - CCP § 491.415

(a) For the purpose of applying for a right to attach order, the defendant's cause of action that is the subject of the pending action or proceeding and the defendant's rights to money or property under a judgment procured in the action or proceeding shall be treated as property subject to attachment.

(b) At the time the plaintiff applies for a right to attach order, the plaintiff may apply for an order permitting creation of a lien under this article. If the plaintiff has already obtained a right to attach order, an application for an order permitting creation of a lien under this article may be applied for in the same manner as a writ of attachment. As a prerequisite to obtaining an order under this subdivision, the plaintiff shall file an undertaking as provided by Sections 489.210 and 489.220.

(c) The defendant may, but is not required to, claim an exemption in a proceeding initiated by the plaintiff for an order permitting creation of a lien under this article. An exemption may be claimed if the money or property sought by the defendant would be exempt from attachment should the defendant prevail in the other action or proceeding. The exemption shall be claimed and determined pursuant to this subdivision in the same manner as an exemption is claimed and determined upon application for a writ of attachment.