It is no secret that the usual advice when it comes to grooming and dressing for med school interviews is to keep it clean, neat, and conservative.
What this usually means in a color-neutral suit for men and the same for women. For women, you have a choice between a pant suit versus a skirt. Any will do as long as you are comfortable and look professional in it. Women may forgo the suit but make sure that your substitute is very personal.
I personally don’t like giving dress codes since a lot of brilliant applicants just have personalities that don’t go with suits and ties. But since this is a one-time thing it is best to just let ones personality shine through via your words rather than as a fashion statement.
As for the accessories make sure not too wear any flashy jewelry. Keep your shoes shiny and clean and if your a woman and comfortable with power heels, then by all means wear them. If you’ll be teetering a tottering as you enter the interview room though, go with a more reasonably-heeled shoe.