Wellmark's main offices are found in the Chicago suburb of Schaumburg and on the northwest edge of Dallas. The Illinois-based group handles sales, marketing, product support, and corporate issues, while the Texas facility focuses on product manufacturing.

The marketing and sales management for all Wellmark brands are directed from the Schaumburg corporate office site. Professionals who are experts in their diverse markets oversee promotional programs, distribution issues, advertising campaigns and product life management. In addition to the various brands, licensing and active ingredient sales are managed in this office. The support functions for Wellmark's brands are housed in Schaumburg including customer service, shipping, regulatory, customer relations, accounting, finance, human resources, legal and information technology. Executive offices and corporate affairs for Wellmark are in the Illinois office.

The Dallas facility is primarily concerned with product manufacturing, warehousing, and product development. The manufacturing capabilities include liquids formulation and filling, extrusion and injection molding, dust blending, and packaging under ISO 9002 and ECGMP guidelines. Analytical labs are GLP EPA/FDA compliant with gas chromatography, mass spectrometry, and liquid chromatography capabilities. The formulations laboratory is experienced in product forms ranging from solids, liquids, aerosols, microemulsions and extrusion/molder with pilot plant capabilities. The field development group includes a multi-species insectary, spray tower/fogging chambers and home environment simulations.

The Canadian division of Wellmark is located in Guelph, Ontario. This office conducts the marketing and sales management, distribution and customer service for all Canadian Wellmark brands.