Mich. Comp. Laws § 493.6

Sec. 6. (1) Every licensee shall maintain at all times net worth in the amount required under section 2. (2) If the commissioner determines at any time that any bond is insecure, exhausted, or otherwise of doubtful validity or collectability, the commissioner may require the licensee to obtain an additional bond in an amount of not more than $1,000.00. The licensee shall file the new bond within 10 days after the commissioner has issued written demand upon the licensee.