Will I need to file an amendment? My taxes have  been accepted & I wasnt expecting this form,  it was almost $20 in interest

The correct answer is to amend your return.  This will have to be your decision.  Maybe the tax on the $20 is 25% or $5.00.  I don't think the IRS will send you a notice for $5.00.  

It is your decision.

Why would the tax on $20 be 25%?  It's just added to your total income which probably won't change anything.

Right, the interest of $20 will be taxed at the same rate as the rest of your income. Generally, the IRS will let a tax difference of less than $25 go.

@GaryB007