As littleadv points out, $13K can be given to each person per year without having to pay or consider gift tax (or even file a gift tax return) and so perhaps as much as $52K might be shielded from gift tax this year if you are buying the condo jointly with your spouse or significant other (SOSO) and your father and his SOSO each gift $13K to you and your SOSO. As for the rest, your father is entitled to a lifetime combined gift and estate tax exclusion in addition to the annual exclusion of $13K per person per which has been varying lately as Congress keeps changing the rules. (I believe the exclusion is $5 million right now and is scheduled to go down to $1 million in the unlikely event that Congress does nothing about it). The remainder of the $70K gift can be counted against this combined exclusion so that no tax will need to be paid right now. Your father will need to file Form 709 with the IRS (not with Form 1040 but with the same due date) which will say $X has been given to you ($Y to your SOSO?) of which $13K per person counts towards the annual exclusion and the balance towards the lifetime combined exclusion. When your father passes away, his estate will be exempt from estate tax up to whatever remains by then of his lifetime exclusion (if he makes similar gifts to your siblings, say). Most estates in the US do not pay any estate tax because the estates are smaller than the exemption. If your father is wealthy enough that reduction of his lifetime exclusion is a serious concern to him, then he will likely have enough lawyers to advise him of alternate strategies anyway.

As littleadv points out, $13K can be given to each person per year without having to pay gift tax (or even file a gift tax return). So perhaps as much as $52K might be shielded from gift tax this year if you are buying the condo jointly with your spouse or significant other (SOSO) and your father and his SOSO each gift $13K to you and your SOSO. As for the rest, your father is entitled to a lifetime combined gift and estate tax exclusion in addition to the annual exclusion of $13K per person per year. The amount of the exclusion has been varying lately as Congress keeps changing the rules. I believe the exclusion is $5 million right now and is scheduled to go down to $1 million in the unlikely event that Congress does nothing about it (reducing or eliminating estate taxes entirely is a high-priority item for one of the political parties). The remainder of the $70K gift can be counted against this combined exclusion so that no tax will need to be paid right now. Your father will need to file Form 709 with the IRS (it is filed separately from Form 1040 but with the same due date) which will say $X has been given to you ($Y to your SOSO?) of which $13K per person counts towards the annual exclusion and the balance towards the lifetime combined exclusion. The gift tax due is thus zero. When your father passes away, his estate will be exempt from estate tax up to whatever remains by then of his lifetime exclusion (if he makes similar gifts to your siblings, say). Most estates in the US do not pay any estate tax whatsoever because the estates are smaller than the exemption. If your father is wealthy enough that reduction of his lifetime exclusion is a serious concern to him, then he will likely have enough lawyers to advise him of alternate strategies anyway.