De Soto Planners Table Merck Animal Health’s $985M Expansion Project

Posted December 2, 2025

​​Merck Animal Health will need to adjust its site plans for an $985 million expansion of its biologics facility in De Soto.

During the City of De Soto Planning Commission meeting in November, city planners voted to table Merck’s site plans to construct 3 buildings at 35500 W 91st Street until the next meeting. The buildings include material management, drug production and a utility building. A small security building and guard house will also be included.

De Soto planners decided to table the discussion item to give the applicant time to address concerns with internal parking, fire lanes and traffic flow for construction work.

The next De Soto Planning Commission meeting is scheduled for December 16.

In May, Merck announced plans to expand its existing facility by 200,000 square feet, including $860 million in investments in its existing facility and $35 million in its research and development laboratories. The development is Merck’s largest investment in company history.

Since its official announcement, the project has increased its cost to $985 million. Additionally, the expansion plans have increased to 240,000 square feet, to be constructed in four phases. During the last De Soto City Council meeting, council members voted to approve industrial revenue bonds. The project will receive a 10-year, 85% property tax abatement for each of the project’s four phases. Merck will make annual payment-in-lieu-of-tax contributions for the project.

Merck is targeting a groundbreaking for the project sometime in the spring of next year.