LANSING, Mich. — All Michigan drivers with auto insurance will receive a $400 per-vehicle refund next year.

Gov. Gretchen Whitmer and state regulators announced the dollar amount Tuesday, more than a month after she had requested the checks by citing a multibillion-dollar surplus in the Michigan Catastrophic Care Association fund. The fund, which is overseen by a board primarily made up of insurance companies, had quickly agreed to issue refunds but waited to release details.

The fun reimburses insurers medical and other costs for people seriously injured in crashes.

“Michiganders have paid into the catastrophic care fund for decades, and I am pleased that the MCCA developed this plan so quickly after unanimously approving my request to return surplus funds to the pockets of Michiganders,” the governor said in a statement.