State transportation officials said in a brief statement on Wednesday that they were working with the Cape Cod Regional Transit Authority on the service, which would operate on weekends only.
The service would be run by the regional authority at no cost to the MBTA.
A spokeswoman for the state Department of Transportation said the trains would likely run between South Station and Hyannis, but specific schedules and fares have not been finalized.
The CCRTA did not immediately return a call.
Gov. Deval Patrick said on his official Twitter account Wednesday that restoring train service to Cape Cod would be a boost for residents and tourists.