Yes, travel on the Bernina Express is "free" with a Swiss Travel Pass, but it is subject to a mandatory seat reservation fee. While your pass covers the actual cost of the ticket (which can be over CHF 60), you cannot board the panoramic carriages without a confirmed reservation. In 2026, these fees vary by season: CHF 40 in the low season and CHF 44 in the high season (May to October). This fee applies even to children. If you want to see the same stunning views without paying the reservation fee, you can take the regular regional trains that run on the same tracks. These regional trains have windows that open (great for photography) and do not require reservations, though they lack the huge glass-dome ceilings and the "tourist" amenities of the official Express train.