What other kind of insurance premium could there be then? It's either property insurance that you pay to an insurance company in case the property is damaged or destroyed, or mortgage insurance that you pay in case for some reason you default on the loan. While there could be other types of insurance, I'm certainly not immediately aware of any that would pertain to residential rental property.
Typically, mortgage insurance premiums are in box 5 of the 1098. Some lenders will list the property insurance as something like "Hazard Insurance" paid from escrow, elsewhere on the 1098 such as in box 10, or at the bottom of box 8.
Knowing exactly what specific insurance entry you are having an issue with, may help to narrow things down a bit.
