Interior designers can specialize in a particular interior design discipline, such as residential and commercial design, with some developing expertise within a niche design area such as hospitality, health care and institutional design. In jurisdictions where the profession is regulated by the government, designers must meet broad qualifications and show competency in the entire scope of the profession, not only in a specialty. Designers may elect to obtain specialist certification offered by private organizations.

Interior designers who also possess environmental expertise in design solutions for sustainable construction can receive accreditation in this area by taking the Leadership in Energy and Environmental Design (LEED) examination.

The specialty areas that involve interior designers are limited only by the imagination and are continually growing and changing. With the increase in the aging population, an increased focus has been placed on developing solutions to improve the living environment of the elderly population, which takes into account health and accessibility issues that can affect the design.

Awareness of the ability of interior spaces to create positive changes in people's lives is increasing, so interior design is also becoming relevant to this type of advocacy.