DES MOINES, Iowa (AP) — The federal tax cut could save up to $147 million in utility bills for Iowa residents as the state’s investor-owned utility companies pass along some of their giant tax reductions.

The Des Moines Register reports that utility companies, like MidAmerican and Alliant, will save millions as part of the new tax law signed by President Donald Trump in December. Legislation lowering the corporate federal income tax rate from 35 percent to 21 percent took effect Jan. 1.

Companies have yet to decide how they’ll return savings to customers. Some are considering lowering rates or providing monthly bill credits.

MidAmerican Energy estimates returning between $90 million and $112 million to customers. Interstate Power & Light says it may return between $18.6 million and $19.6 million. Alliant’s gas customers could see between $500,000 and $3.7 million.