Hello and thank you for your question.
IRC 508 sets forth special rules with respect to IRC 501(c)(3) charitable non-profit organizations. By saying you are going to start an IRC 508 trust, I assume you mean that you will have an IRC 501(c)(3) organization that is taxed as a private foundation.
The IRS used to have an advance ruling process due to IRC 508(b), which states that, "
The IRS has since scrapped that process. See here for more information:
Without any more ado now, the answer to your question: Form 1023, here:
You can use the IRS online application too, here:
Michigan may also have some forms to file. If you want exemption from sales tax, for example, if you solicit donations of more than $25,000, or if the non-profits revenues exceed $250K / $500K requiring you to have an annual review or audit of your financial statements.
The state of Michigan gives more information here:
"The Charitable Trust Section is charged with the administration and enforcement of four Michigan Statutes. Those statutes regulate charitable organizations, police and fire organizations, professional fundraisers that solicit donations and plan campaigns in Michigan, and charitable organizations that hold charitable assets in Michigan. Each statute is discussed separately below with a summary of who is subject to the law and what the organization or fundraiser must do to comply."
I hope this information is helpful to you. Thank you again for your question!