It will depend on the institution as well as what the "home" program for the fellowship is. For example if it's run out of neurology you may be paid as a PGY5 as they would assume a base 4 year neurology residency. This information is probably best asked directly of the GME office at the institutions you're considering. The actual monetary difference may be relatively minimal since it is only a one year fellowship. More important will be any restrictions of moonlighting that you may wish to undertake as a fully BE/BC pulmonologist.