((a)) ** Liens for estate tax** Except as otherwise provided in subsection (c)—
((1)) ** Upon gross estate** Unless the estate tax imposed by chapter 11 is sooner paid in full, or becomes unenforceable by reason of lapse of time, it shall be a lien upon the gross estate of the decedent for 10 years from the date of death, except that such part of the gross estate as is used for the payment of charges against the estate and expenses of its administration, allowed by any court having jurisdiction thereof, shall be divested of such lien.
((2)) ** Liability of transferees and others** If the estate tax imposed by chapter 11 is not paid when due, then the spouse, transferee, trustee (except the trustee of an employees’ trust which meets the requirements of section 401(a)), surviving tenant, person in possession of the property by reason of the exercise, nonexercise, or release of a power of appointment, or beneficiary, who receives, or has on the date of the decedent’s death, property included in the gross estate under sections 2034 to 2042, inclusive, to the extent of the value, at the time of the decedent’s death, of such property, shall be personally liable for such tax. Any part of such property transferred by (or transferred by a transferee of) such spouse, transferee, trustee, surviving tenant, person in possession, or beneficiary, to a purchaser or holder of a security interest shall be divested of the lien provided in paragraph (1) and a like lien shall then attach to all the property of such spouse, transferee, trustee, surviving tenant, person in possession, or beneficiary, or transferee of any such person, except any part transferred to a purchaser or a holder of a security interest.
((3)) ** Continuance after discharge of fiduciary** The provisions of section 2204 (relating to discharge of fiduciary from personal liability) shall not operate as a release of any part of the gross estate from the lien for any deficiency that may thereafter be determined to be due, unless such part of the gross estate (or any interest therein) has been transferred to a purchaser or a holder of a security interest, in which case such part (or such interest) shall not be subject to a lien or to any claim or demand for any such deficiency, but the lien shall attach to the consideration received from such purchaser or holder of a security interest, by the heirs, legatees, devisees, or distributees.
((b)) ** Lien for gift tax** Except as otherwise provided in subsection (c), unless the gift tax imposed by chapter 12 is sooner paid in full or becomes unenforceable by reason of lapse of time, such tax shall be a lien upon all gifts made during the period for which the return was filed, for 10 years from the date the gifts are made. If the tax is not paid when due, the donee of any gift shall be personally liable for such tax to the extent of the value of such gift. Any part of the property comprised in the gift transferred by the donee (or by a transferee of the donee) to a purchaser or holder of a security interest shall be divested of the lien imposed by this subsection and such lien, to the extent of the value of such gift, shall attach to all the property (including after-acquired property) of the donee (or the transferee) except any part transferred to a purchaser or holder of a security interest.
((c)) ** Exceptions**
((1)) The lien imposed by subsection (a) or (b) shall not be valid as against a mechanic’s lienor and, subject to the conditions provided by section 6323(b) (relating to protection for certain interests even though notice filed), shall not be valid with respect to any lien or interest described in section 6323(b).
((2)) If a lien imposed by subsection (a) or (b) is not valid as against a lien or security interest, the priority of such lien or security interest shall extend to any item described in section 6323(e) (relating to priority of interest and expenses) to the extent that, under local law, such item has the same priority as the lien or security interest to which it relates.