The improvements to rail infrastructure between the Stalybridge tunnel and Diggle are part of wider plans to upgrade Transpennine services between Manchester, Leeds and York.
Mossley station would be moved 985 ft (300m) north of its current location and given a new footbridge, with lifts to allow step-free platform access.
The changes would include access to and from Manchester Road.
Platforms at Greenfield station, meanwhile, would be extended to allow longer trains to use it.
A new footbridge with lifts would also be installed.