My brother is giving me $40,000. Do I pay tax on it if I put it into savings.

[DoninGA]

If this is a gift then you do not report the gift received on your tax return, regardless of the amount received.  Any interest received for the amount deposited into the savings account would be taxable.

Your brother, as the giver of the gift, would have to file a Gift Tax Return, IRS Form 709, to report the gift since it is greater than $14,000 given to a single individual during the tax year.