The receipt of a cash inheritance is not reported on a federal tax return.
However, if the amount of inheritance received from a foreign individual is greater than $100,000 you will have to file a Form 3520 to inform the IRS of receiving the income.
Go to this IRS website for Form 3520 - https://www.irs.gov/forms-pubs/about-form-3520
Form 3520 is Not sent with or included with your federal tax return, it is a stand-alone form that has to be filed on or before the due date of a federal tax return for the tax year in which the funds were received.
