Interior design companies in the United States can be categorized into several types, each specializing in different aspects of design and client needs. These types include residential design firms, commercial design firms, corporate design firms, hospitality design firms, and specialized design firms.

Residential design firms focus on the design of private homes, apartments, and condominiums. They cater to individual clients seeking personalized spaces that reflect their lifestyle and preferences. Commercial design firms, on the other hand, are involved in the design of office buildings, retail spaces, and public areas. Corporate design firms specialize in creating workspaces for companies, emphasizing functionality and brand representation. Hospitality design firms focus on hotels, restaurants, and resorts, ensuring that the design enhances the guest experience. Lastly, specialized design firms may focus on specific areas such as kitchen and bath design, sustainable design, or historical preservation.

The diversity in types of interior design companies is driven by the varied needs of clients and the complexity of projects. According to the American Society of Interior Designers (ASID), there were approximately 22,000 interior designers employed in the United States as of 2020. This figure highlights the significant demand for interior design services across various sectors. The different types of firms allow for a wide range of expertise and specialization, ensuring that clients can find the perfect match for their specific design needs.