Mich. Comp. Laws § 445.1305
The holder of a home improvement installment contract, upon agreement in writing with the buyer, may refinance the payment of the unpaid time balance of the contract by providing for a new schedule of installment payments. The holder may charge and contract for the payment of a refinanced charge by the buyer and collect and receive the same, but such refinance charge shall be based upon the amount refinanced, plus any additional cost of insurance and of official fees incident to such refinancing, after the deduction of a refund credit in an amount equal to that to which the buyer would have been entitled under section 303 if he had prepaid in full his obligations under the contract or contracts, computed without allowance for any minimum earned finance charge. Such refinance charge shall not exceed the rate of finance charge provided under section 301. The agreement for refinancing may also provide for the payment by the buyer of the additional cost to the holder of the contract of premiums for continuing in force, until the maturity of the contract as refinanced, any insurance coverages provided therein. The refinancing agreement shall set forth the amount of the unpaid time balance to be refinanced, the amount of any refund credit, the amount to be refinanced after the deduction of the refund credit, any additional premiums paid for insurance and of official fees to the buyer, the amount of the finance charge under the refinancing agreement, the new unpaid time balance and the new schedule of installment payments. A refinancing agreement between a financing agency and a buyer may consolidate the new unpaid time balances of 2 or more home improvement installment contracts by providing for a new schedule of consolidated installment payments, and may provide for the acceleration of the consolidated time balance upon a failure of the buyer to pay in full any consolidated installment payment. A contractor may not consolidate 2 or more home improvement installment contracts except to the extent provided in sections 306, 307 and 308.
MCL 445.1305