IRS Form 709, United States Gift (and Generation-Skipping Transfer) Tax Return instructions - https://www.irs.gov/pub/irs-pdf/i709.pdf
For gifts made to spouses who are not U.S. citizens, the annual exclusion has increased to $155,000
If you have exceeded the annual exclusion amount of $15,000 for a gift given to an individual, not your spouse, you are required to file a Form 709. If you gift over $155,000 to your foreign spouse then you are required to file a Form 709
