Sorry for the delayed response. I was away from the computer. If the cash that you inherited is $100,000 or more, you need to complete the Form 3520, which is an information form. If the amount of cash inherited is less than $100,000, there is no reporting requirement. SEE BELOW:
You must file Form 3520, Annual Return to Report Transactions with Foreign Trusts and Receipt of Certain Foreign Gifts, if, during the current tax year, you treat the receipt of money or other property above certain amounts as a foreign gift or bequest. Include on Form 3520:
You must aggregate gifts received from related parties. For example, if you receive $60,000 from nonresident alien A and $50,000 from nonresident alien B, and you know or have reason to know they are related, you must report the gifts because the total is more than $100,000. Report them in Part IV of Form 3520. Treat gifts from foreign trusts as trust distributions you report in Part III of Form 3520.
File Form 3520 separately from your income tax return. The due date for filing Form 3520 is the same as the due date for filing your annual income tax return, including extensions. You file an annual Form 3520 for all reportable foreign gifts and bequests you receive during the taxable year. See the Instructions for Form 3520 for additional information.
Link to Form 3520/instructions:
Let me know if this clarifies matters for you.