Yes, in 2026, assigned seating is a standard feature for all high-speed and long-distance trains in Spain, including the AVE, Alvia, and Euromed services operated by Renfe, as well as competitors like Ouigo and Iryo. When you purchase a ticket, a specific car and seat number are automatically assigned to you, ensuring you have a place to sit even on the busiest routes. For many ticket types (such as "Elige" or "Premium"), you can choose your specific seat from a map for a small fee or as part of the package. This system provides a much more relaxed boarding process compared to "first-come, first-served" regional trains. However, it is important to note that Cercanías (commuter) and most Media Distancia (regional) trains do not have assigned seats; on these, you simply find any available spot. Always check your ticket carefully for the "Coche" (car) and "Plaza" (seat) numbers, and remember that for high-speed travel, your ID must match the name on the ticket, as security checks are common at major Spanish stations.