I don't know if Michigan's regular "Where's My Refund" tool will find an amended return or not. I know the Federal IRS has separate tools. But I don't quickly find a separate tool at the Michigan "Where's My Refund" website.
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Did you try the regular Michigan tool, just in case? Otherwise, you may need to phone the Michigan Dept of Treasury and ask them the status, and while you have them on the line, ask if there's a separate tool on their website or not.
