US advertising spending is projected to grow 9.5% year-on-year in 2026, driven largely by digital channels and the increasing use of artificial intelligence in marketing, according to a new forecast by the Interactive Advertising Bureau (IAB).
The outlook is based on a study of more than 200 US brand and agency buyers and points to a shift in how advertisers plan, execute, and measure campaigns. Rather than focusing primarily on reach, marketers are increasingly prioritising performance, retention, and automation.
IAB said the transition from small-scale AI experiments to more advanced, agent-led systems is expected to be a major driver of growth. These systems are being used to manage budgets, optimise creative assets, and adjust audience targeting in real time.
AI is now central to marketing strategies, the study found, with 73% of marketers optimising their content for AI-generated answers. This is changing how advertising creative is structured and how brands are discovered online.
Despite growing adoption, marketers continue to face challenges. Adapting to changing consumer behaviour has emerged as the top media investment concern for 2026, overtaking worries about macroeconomic uncertainty that dominated in 2024.
The report also highlights that marketers are moving beyond AI tools that simply assist teams, towards systems that act autonomously on their behalf. This shift is expected to influence how budgets are planned, how media strategies are built, and how spending decisions are made throughout the year.
IAB said advertisers will need to strengthen their first-party data, test measurement systems across platforms, and design creative that can be effectively interpreted by AI to stay competitive in an increasingly automated advertising landscape.
