Potentially, prosecutors will offer alternative sentencing on a third offense, but it depends on the circumstances of the case, such as how much time was between the DUIs. They also take into consideration the circumstances of the person who charged, such as if there is a serious alcohol problem or if the person is hospitalized. It will depend on the circumstances of a particular DUI investigation whether the government thinks they have a strong or weak case.
In some cases, a DUI attorney will be able to negotiate alternative sentencing, and they do not involve a specific mandatory sentence and can be beneficial offers to be obtained.