It sounds like you're mixing up various loan programs, which is leading to your confusion. The primary federal loans for medical students are stafford loans, which have an annual cap of $40,500 (I believe this increases to somewhere around $45k for your 3rd and 4th year). You also might maybe get a few thousand dollars in Perkins loans, but those are generally small loans and awarded at your school's discretion.
So Stafford and Perkins loans would not be enough to cover the costs of attending KCUMB if you include living expenses. However, the good news is that you can borrow all the GradPlus loans you need for certified school expenses beyond what you get with Stafford and Perkins loans. The certified cost of attendance at KCUMB is probably somewhere around $60k ($38k for tuition and $22k for living expenses, fees, etc.). Assuming you don't get Perkins loans, you can borrow $40,500 of that in Staffords and $19,500 in GradPlus loans. If you get a Perkins loan, that should reduce the GradPlus amount.
About your income, it probably won't have any impact because the majority of federal loans are not need-based. Perkins loans are need-based but again arbitrary, and most of us never see them. Only the subsidized Staffords are need-based, and those are capped at $8500/year. Neither the unsubsidized staffords (the additional $32,000 you'd borrow to get to $40,500) or the GradPlus loans are need-based. So assuming your income is super high, the worst case scenario would be that you wouldn't get any subsidized staffords, so the full $40,500 would be unsubsidized. But assuming the KCUMB COA of $60k, your EFC (expected family contribution calculated by the government following completion of the FAFSA) would have to be greater than $58,500 for you to not qualify for the full $8500 -- your EFC is subtracted from the COA to determine your need for awarding subsidized loans.
So in a nutshell, you should be able to borrow the money you need.
