Title says "postbac masters" which means grad school, which doesn't touch your undergrad GPA, and undergrad GPA is usually the problem.
For the sake of planning, if you have above a 3.0, and you already have a confidence-inspiring MCAT (such as 510+) and you already have produced multiple very strong 3.7+ full time mostly science undergrad years as part of that 3.0 undergrad work, then proceed to SMP land (if that's what you mean by "postbac masters"). Understand that SMPs are expensive and very hard work and are limited in what they can do for you.
Otherwise you need more undergrad until you have multiple very strong 3.7+ full time mostly science undergrad years. A second bachelors is one way to do that.
Or consider the DO masters programs that offer a more stable pathway into med school.
Best of luck to you.
