Son owes around $250k. I would like to forgive this debt as a "gift". Do I need to forgive the max amount each year for the next x number of years to accomplish this with no taxes to either of us, or can I use the full amount now since it is below the lifetime max? Thanks.
Gift received are never reported on a tax return.
You can gift the full amount now assuming you are under the lifetime exclusion of $12.92 million in 2023 so no taxes would be owed. But you will have to file the IRS form 709.
IRS Form 709 - https://www.irs.gov/forms-pubs/about-form-709
You will not incur any gift tax liability until you reach the 2023 lifetime exemption of $12.92 million.
If your individual gift is valued at more than $17,000 to one other person (e.g., your son), then you will have to file a gift tax return (Form 709), but there will be no tax due until you surpass the limit noted above.