Northwestern’s HPML program requires Chemistry. It is not recommended, it is required.
http://www.feinberg.northwestern.edu/education/degree-programs/hpme/entrance-requirements.html
Others, like Brown’s PLME program and Rice/Baylor Medical Scholars Program require two science subject tests, but are not specific about what two.
Some, like Pittsburgh’s Guaranteed Admissions Program or Alabama’s Early Medical School Acceptance Program do not require subject tests at all.
That being said, if you have not taken enough Chemistry in high school, or if you did not do well in the subject, it could be a concern/red flag to many of those programs.