Y Combinator now runs four batches per year, Winter, Spring, Summer, and Fall, up from two in 2024, with roughly 60% of companies in 2026 batches AI-focused, up from 40% two years earlier. The Fall 2026 batch runs October through December, primarily in person in San Francisco, culminating in a Demo Day on December 2, 2026.
Doubling batch frequency is a capacity decision as much as a strategic one: if AI-focused applications are arriving faster than a twice-yearly cycle can process, running more frequent, likely smaller, batches is the more straightforward fix compared with trying to scale a single cohort's size without diluting the mentorship Y Combinator is known for.