An Owner's Policy is valid for as long as the property is owned by the purchaser, and up to the purchase price or value on that property. The one time premium paid is optional - either at the time of purchase or at a later date. Nevertheless, an Owner's Title Insurance Policy provides a lifetime of protection to that specific owner against title defects that could otherwise affect that purchaser's claim to the parcel of property.
A Lender's Policy protects the interest of the lender up to the value of the loan issued and is typically always required. A new policy must be issued for every new loan issued on a piece of property. The one time premium is paid at the time of the closing, and concludes once the loan is paid off.