In 2026, the Eurail Pass works on most regional and "local" commuter trains, but it does not work on urban "Metros" (subways), trams, or city buses. For instance, you can use your pass on the S-Bahn in Germany or the RER in Paris (for lines operated by the national rail company, SNCF), but you cannot use it on the Paris Métro or the London Underground. The general rule in 2026 is: if the train is operated by one of the 33 national railway companies (like Trenitalia, Renfe, or DB), it is likely covered. However, many "local" regional trains in 2026 now require a digital "check-in" via the Eurail Rail Planner app before boarding. While these local trains are "free" with your pass, high-speed and overnight trains (like Eurostar or TGV) still require a separate seat reservation fee, which is not included in the pass price. Always check the "Network Map" in the 2026 Eurail app to confirm if a specific private local line is an "associated partner" or excluded.