Yes, you can gift your son $500,000, but there are federal tax reporting requirements you must follow because this amount significantly exceeds the annual gift tax exclusion. In 2026, the annual exclusion is $19,000 per person. Any amount you gift over that $19,000 limit—in this case, $481,000—must be reported to the IRS on Form 709. While you must report the excess, you likely will not have to pay actual "gift tax" out of pocket. Instead, this amount will be applied against your federal lifetime gift and estate tax exemption, which is $15 million in 2026. You only begin to owe federal gift tax once your cumulative lifetime gifts exceed that $15 million threshold. You should consult a tax professional to handle the required filings properly.