New Technology Train (NTT) is the collective term for the modern passenger fleet of the New York City Subway that has entered service since the turn of the 21st century. This includes the current R142, R142A, R143, R160, R179, R188 and R211 models, along with the planned R262 and R268 models. Two prototypes, the R110A and R110B, were used to test the features that would be found on all NTT trains today.

The R211 is a new technology train (NTT) New York City Subway car being built by Kawasaki Railcar Manufacturing for the B Division and the Staten Island Railway (SIR). They will replace two aging subway car models: all R44 cars on the Staten Island Railway and all R46 subway cars. The order is split into three parts: R211A and R211T cars for the subway and R211S cars for the SIR. The R211Ts employ open gangways between cars, allowing passengers to see and walk through the entire length of the train – a feature not present on the subway's other rolling stock. The base order consists of 535 cars, with options for up to 1,077 additional cars.