Your monthly insurance premium will continue until you have paid your balance down to 78% AND be in your FHA loan for FIVE years. If you refinance into a fifteen year, you will not have a monthly premium at your LTV but you will have an upfront premium. You will have a pro-rated portion of your upfront premuim refunded if you refinance within the first three years of your FHA loan.

To my knowledge, you need to be at 78% of the Original purchase amount and pay AT LEAST 5 years of MIP before you can drop it. Most folks refi out of FHA when then hit 78% and go conventional so you dont have to pay the up front UFMIP (1.75%) and the monthly.

Ask your mortgage broker who would have the entire financial file of your & documents regarding your property. All placed in a "formula" then broker can discuss what is too your best interest. Without reviewing your files difficult render an opinion in your favor.