If my lease is terminated, does the landlord have to return my security deposit or any prepaid rent?
You are required to pay rent for the month after you give notice to your landlord. However, you are not obligated to pay rent as of the first day of the second month that rent is due after your notice is submitted, assuming that you have vacated the unit by then. For example, if you give the written statement and documents to your landlord on October 20th, you are required to pay November’s rent on November 1 but you are not required to pay rent on December 1st (assuming you are out of the apartment before December 1st). However, your landlord is not required to return any prepaid rent, including first and last months’ rent.
In terms of your security deposit, your landlord cannot keep your security deposit just because you are ending your lease early. Your landlord can only keep your security deposit if s/he would otherwise be allowed to under the law* – for example, due to damage that you caused to the rental unit.**
* M.C.L. § 554.601b(2)
** M.C.L. § 554.607