In the case of any estate with respect to which an election has been made under section 6166, if the executor makes an election under this section (at such time and in such manner as the Secretary shall by regulations prescribe) and files the agreement referred to in subsection (c), the deferred amount (plus any interest, additional amount, addition to tax, assessable penalty, and costs attributable to the deferred amount) shall be a lien in favor of the United States on the section 6166 lien property.
If the value required as section 6166 lien property pursuant to paragraph (2) exceeds the value of the interests in property covered by the agreement referred to in subsection (c), the Secretary may accept bond in an amount equal to such excess conditioned on the payment of the amount extended in accordance with the terms of such extension.
The lien imposed by this section shall not be valid as against any purchaser, holder of a security interest, mechanic’s lien, or judgment lien creditor until notice thereof which meets the requirements of section 6323(f) has been filed by the Secretary. Such notice shall not be required to be refiled.
The lien imposed by this section shall arise at the time the executor is discharged from liability under section 2204 (or, if earlier, at the time notice is filed pursuant to paragraph (1)) and shall continue until the liability for the deferred amount is satisfied or becomes unenforceable by reason of lapse of time.
In the case of any real property subject to a lien for repair or improvement, as against a mechanic’s lienor.
If at any time the value of the property covered by the agreement is less than the unpaid portion of the deferred amount and the required interest amount, the Secretary may require the addition of property to the agreement (but he may not require under this paragraph that the value of the property covered by the agreement exceed such unpaid portion). If property having the required value is not added to the property covered by the agreement (or if other security equal to the required value is not furnished) within 90 days after notice and demand therefor by the Secretary, the failure to comply with the preceding sentence shall be treated as an act accelerating payment of the installments under section 6166(g).