Based on the instructions from the SOS website, both public and private pensions are eligible for a "subtraction" if one or both of the taxpayers were born before 1946. Instructions are on page 17 of the Michigan Tax Instruction booklet - there is a section called "which sections do I complete" - see option 3 regarding taxpayers born prior to 1946. There is also a scenario #4 which gives a step-by-step for a situation where one spouse is older than the other and both public and private pensions are involved. You will need form
4884 which includes a section to identify the pension income and their sources. Then complete section "A". Unfortunately, TurboTax does not have this totally correct in their programming - they do not allow reporting private pensions. I had to do the form manually, print the return and send it in by mail.