Laws and regulations regarding loan interest rates and APRs can vary from state to state. Some states have interest rate minimums and maximums that all lenders must abide by, while other states have little to no regulation regarding these loan factors. You can talk to your individual lender about specific interest rates and terms available in your area.
To get the best interest rates on a cosigned personal loan, it is important to choose a cosigner with a good credit score, sufficient income, and capability of repaying the loan.