The board will vote Thursday on the compromise deal that is supposed to get construction under way again.
All work on the museum stopped 10 months ago due to a dispute over funding and contractual issues.
If the commissioners approve the deal, construction could resume by October 4.
The underground museum is to house such artifacts as the staircase workers used to escape the attacks. Visitors also will be able to see portraits of the nearly 3,000 victims and hear oral histories of Sept. 11.
The memorial includes a plaza, where waterfalls fill the fallen towers' footprints. Almost 4.5 million people have visited it since it opened last September.