The use of the inner marker in this case is the standard procedure for US operators; however, it must be approved in that carrier's Op Specs. Not all carrier's programs incorporate this. If they do not, the approach is not authorized.
AC 120-29A also references the use of the baro DA or the IM, whichever comes first. This is another option that must be included in the carrier's Op Specs.
In no case (that I am aware of) can a US operator use only the DA.