About Mid-Island Mortgage Corp. Stability, experience, and reliability since 1959. What separates Mid-Island Mortgage Corp. from other lenders is our unique ability to deliver strong, solid home lending with personalized, individual service to best fit your specific needs. Mid-Island has been serving the local community for over 50 years, we’re your friends and neighbors and know your town first hand... that’s something that can’t be said about the many giant, national mortgage corporations.