McCarthy Building Companies Leads Construction of 400,000-Square-Foot Facility Aimed at Expanding Access to Specialty and Emergency Services

WENTZVILLE, MO — May 2025 – Mercy has officially broken ground on Mercy Hospital Wentzville, launching construction of the state’s first new, full-service acute care hospital campus in nearly 10 years. The new facility represents a major investment in the health and wellbeing of one of Missouri’s fastest-growing regions.

Designed to meet the increasing demand for advanced health care services in St. Charles County and surrounding communities, the 400,000-square-foot hospital will include:

• 75 inpatient acute care beds
• A 26-bed emergency department featuring two trauma areas and four behavioral health rooms
• Surgical suites and comprehensive specialty care, including cardiovascular, oncology, orthopedics, and more
• Outpatient diagnostic, imaging, and treatment services

Once complete, the hospital will offer residents convenient access to critical services in a modern, patient-centered facility that supports both inpatient and outpatient care needs.

McCarthy to Lead Construction

McCarthy Building Companies is serving as general contractor for the multi-phase project. Site preparation began in late March, and work on the hospital’s central utility plant will begin this summer. The main hospital tower is scheduled to begin construction in early 2026. The entire project is expected to take approximately four years to complete.

“This is more than just a hospital — it's a long-term investment in the health of our community,” said a Mercy spokesperson. “We’re building a facility that not only meets today’s needs but is designed to adapt for the future of care.”

Supporting Firms and Design Partners

The hospital is being designed by CannonDesign, an architecture and design firm with a national reputation for health care innovation. Engineering services are being led by IMEG, helping ensure energy efficiency, safety, and operational flexibility in the facility's infrastructure.

When finished, Mercy Hospital Wentzville will anchor a larger medical campus that could eventually include outpatient clinics, physician offices, and wellness services — providing a continuum of care for residents in western St. Charles County and beyond.

Meeting Regional Growth and Demand

Wentzville has seen rapid population growth over the past decade, and the addition of a major acute care hospital will help meet growing health care demands while relieving pressure on existing facilities in the region.

With a focus on advanced technology, modern patient experiences, and clinical excellence, the new hospital will also support job creation in health care and construction, as well as long-term economic development in the region.

Project at a Glance:

• Location: Wentzville, Missouri
• Hospital Size: 400,000 square feet
• Beds: 75 acute care, 26 emergency (including trauma and behavioral health)
• Completion Timeline: Expected within four years
• Project Partners:
  • General Contractor: McCarthy Building Companies
  • Design: CannonDesign
  • Engineering: IMEG

Originally reported by Mccarthy.