IRS FATCA Form 8938 and the FBAR Form TD F 90-22.1

For US citizens and US permanent residents, you must file Form 8938 (also known as the FATCA Form) if your overseas investment assets are above $50,000 for an individual or $100,000 for a married couple (filing jointly) at year end. Additionally, on any given day during the year if your assets are above $75,000 for an individual or $150,000 for a married couple (filing jointly), you will also be required to file the FATCA Form. (If you are married but file separate tax returns, follow the rules for an individual.)

For US Citizens living abroad, you must file the Form 8938 if your overseas investment assets are above $200,000 for an individual or $400,000 for a married couple (filing jointly) at year end. Additionally, on any given day during the year if your assets are above $300,000 for an individual or $600,000 for a married couple (filing jointly), you will also be required to file the FATCA Form.

The IRS has listed a helpful chart of what assets count towards the reporting threshhold.  Note, ownership of foreign real estate outside of the United States does not need to be reported on the FATCA Form if you own it directly, but it does need to be reported if you own it through a foreign entity.

The FATCA Form should not be confused with Form TD F 90-22.1 (FBAR). The FBAR form relates strictly to foreign bank accounts that hold more than $10,000 at any time during the year for ALL foreign bank accounts. This can be a real problem for individuals who own small accounts held in multiple countries that fluctuate greatly against the US Dollar. 

A good rule of thumb is that if must file a FATCA Form 8938, you should almost always be filing a FBAR Form as well.

The penalties for failure to file Form 8938 can be quite high. If you do not file an accurate Form 8938 in a timely manner, there is a $10,000 penalty.  If the IRS asks for a FATCA form and you refuse to comply, they may assess you with a $50,000 penalty for noncompliance.  Form 8938 should be filed along with your income tax Form 1040.

The penalties for failure to file the FBAR Form can also be quite high. If you do not file an accurate FBAR in a timely manner, they may assess up to a $10,000 penalty for each non-willful violation or the greater of $100,000 or 50% of the highest account balance for willful violations.  The FBAR must be filed by June 30th - there is no ability to extend this deadline.
Finally, other individuals subject to the US taxing authority may also be required to complete the FATCA form.