Financial firms are benefiting from the $1.5 trillion tax cut and make up the majority of companies so far handing out raises and bonuses as a result of the bill.
Some utilities say they will pass savings from the tax law to ratepayers. Attorneys general in several states are calling for federal action as well.
Supporters say the recently approved tax law will help American multinationals compete more aggressively overseas. Others see incentives to put factories overseas.
Other countries may need to cut corporate taxes to stay competitive. But companies outside the United States also worry the bill discriminates against them.
Fannie Mae and Freddie Mac will be allowed to keep $3 billion as capital cushion to prevent against losses activated by the Republican tax bill.
Financial firms would see a larger tax cut than manufacturers, a University of Pennsylvania study concluded.