Initiating and Filing for Alimony. To initiate alimony in Illinois, the petitioning spouse must request it in the petition for dissolution of marriage.Learn about the types of alimony available in Illinois, how it's calculated, and the factors courts consider when awarding spousal maintenance. Using the Illinois guidelines, there is a basic formula for calculating spousal maintenance. Navigate alimony and settlement discussions in Illinois with our stepbystep guide. Ensure financial readiness for a smoother process. Spousal maintenance, also called alimony or spousal support, is the transfer of money from one former spouse to the other on an ongoing basis - usually monthly. This alimony calculator is intended only to give a general idea of your spousal maintenance calculations. Spousal maintenance is not automatically granted in Illinois divorce cases, and it will typically only be awarded if a spouse can demonstrate a financial need. The Illinois Marriage and Dissolution of Marriage of Act sets out three different types of maintenance: fixed-term, reviewable, and indefinite.