The National Association for Interpretation (NAI) is a 501(c)(3) not-for-profit professional organization dedicated to advancing the profession of heritage interpretation, currently serving about 5,000 members in the United States, Canada, and over thirty other nations. Individual members include those who work at parks, museums, nature centers, zoos, botanical gardens, aquariums, historical and cultural sites, commercial tour companies, and theme parks. Commercial and institutional members include those who provide services to the heritage interpretation industry.