University of Maryland vs University of Massachusetts Amherst

What major did you apply for at UMD? What did your guidance counselor say when you were rejected last year? Were your grades/test scores/something else significantly lower than those of students who were accepted from your high school?

Your best bet for transferring into UMD is to complete the MTAP at a community college. https://www.admissions.umd.edu/apply/admission-requirements/transfer-applicant-requirements/maryland-transfer-advantage-program

That said, UMD accepts a fair number of transfers from other universities each year. Go ahead and apply this year if you want to.