Dive summary:

• It's hardly unusual for subcontractors when the primary contractor or owner retaining some of their money due until certain milestones have been passed or work is complete, but the rules can vary, and the American Subcontractors Association has a manual to help explain the variations.
• "Retainage Law in the 50 States" looks at the rules in each jurisdiction and possible differences between the requirements for public and private projects.
• In some states, the guide notes, subs can post securities in place of having their fees retained.

From the article:

The ASA-member law firm and ASA general counsel, Kegler, Brown, Hill and Ritter, Columbus, Ohio, prepared the manual, which contains contributions from construction attorneys from across the country. ...