Public utilities: electric utilities; distribution grid plans created by electric utilities; require. Amends sec. 6a of 1939 PA 3 (MCL 460.6a).

HB 4978 amends Michigan's Public Utilities Act to change the process for utilities seeking rate increases. It requires electric utilities serving over 1 million customers to coordinate with the Public Service Commission (PSC) before filing rate cases to avoid overlapping filings, and the PSC may order a 21-day spacing between such filings. Gas utilities serving fewer than 1 million customers can now request partial, immediate rate relief, with the PSC required to decide within 180 days. If the PSC doesn't issue a final order within 180 days for a rate case, the utility may implement the proposed rate increase but must refund overpayments if the final order is lower.