28 U.S.C. § 2410 : US Code - Section 2410: Actions affecting property on which United States has lien

      (a) Under the conditions prescribed in this section and section
    1444 of this title for the protection of the United States, the
    United States may be named a party in any civil action or suit in
    any district court, or in any State court having jurisdiction of
    the subject matter - 
        (1) to quiet title to,
        (2) to foreclose a mortgage or other lien upon,
        (3) to partition,
        (4) to condemn, or
        (5) of interpleader or in the nature of interpleader with
      respect to,

    real or personal property on which the United States has or claims
    a mortgage or other lien.
      (b) The complaint or pleading shall set forth with particularity
    the nature of the interest or lien of the United States. In actions
    or suits involving liens arising under the internal revenue laws,
    the complaint or pleading shall include the name and address of the
    taxpayer whose liability created the lien and, if a notice of the
    tax lien was filed, the identity of the internal revenue office
    which filed the notice, and the date and place such notice of lien
    was filed. In actions in the State courts service upon the United
    States shall be made by serving the process of the court with a
    copy of the complaint upon the United States attorney for the
    district in which the action is brought or upon an assistant United
    States attorney or clerical employee designated by the United
    States attorney in writing filed with the clerk of the court in
    which the action is brought and by sending copies of the process
    and complaint, by registered mail, or by certified mail, to the
    Attorney General of the United States at Washington, District of
    Columbia. In such actions the United States may appear and answer,
    plead or demur within sixty days after such service or such further
    time as the court may allow.
      (c) A judgment or decree in such action or suit shall have the
    same effect respecting the discharge of the property from the
    mortgage or other lien held by the United States as may be provided
    with respect to such matters by the local law of the place where
    the court is situated. However, an action to foreclose a mortgage
    or other lien, naming the United States as a party under this
    section, must seek judicial sale. A sale to satisfy a lien inferior
    to one of the United States shall be made subject to and without
    disturbing the lien of the United States, unless the United States
    consents that the property may be sold free of its lien and the
    proceeds divided as the parties may be entitled. Where a sale of
    real estate is made to satisfy a lien prior to that of the United
    States, the United States shall have one year from the date of sale
    within which to redeem, except that with respect to a lien arising
    under the internal revenue laws the period shall be 120 days or the
    period allowable for redemption under State law, whichever is
    longer, and in any case in which, under the provisions of section
    505 of the Housing Act of 1950, as amended (12 U.S.C. 1701k), and
    subsection (d) of section 3720 of title 38 of the United States
    Code, the right to redeem does not arise, there shall be no right
    of redemption. In any case where the debt owing the United States
    is due, the United States may ask, by way of affirmative relief,
    for the foreclosure of its own lien and where property is sold to
    satisfy a first lien held by the United States, the United States
    may bid at the sale such sum, not exceeding the amount of its claim
    with expenses of sale, as may be directed by the head (or his
    delegate) of the department or agency of the United States which
    has charge of the administration of the laws in respect to which
    the claim of the United States arises. In any case where the United
    States is a bidder at the judicial sale, it may credit the amount
    determined to be due it against the amount it bids at such sales.
      (d) In any case in which the United States redeems real property
    under this section or section 7425 of the Internal Revenue Code of
    1986, the amount to be paid for such property shall be the sum of -
    
        (1) the actual amount paid by the purchaser at such sale
      (which, in the case of a purchaser who is the holder of the lien
      being foreclosed, shall include the amount of the obligation
      secured by such lien to the extent satisfied by reason of such
      sale),
        (2) interest on the amount paid (as determined under paragraph
      (1)) at 6 percent per annum from the date of such sale, and
        (3) the amount (if any) equal to the excess of (A) the expenses
      necessarily incurred in connection with such property, over (B)
      the income from such property plus (to the extent such property
      is used by the purchaser) a reasonable rental value of such
      property.

      (e) Whenever any person has a lien upon any real or personal
    property, duly recorded in the jurisdiction in which the property
    is located, and a junior lien, other than a tax lien, in favor of
    the United States attaches to such property, such person may make a
    written request to the officer charged with the administration of
    the laws in respect of which the lien of the United States arises,
    to have the same extinguished. If after appropriate investigation,
    it appears to such officer that the proceeds from the sale of the
    property would be insufficient to wholly or partly satisfy the lien
    of the United States, or that the claim of the United States has
    been satisfied or by lapse of time or otherwise has become
    unenforceable, such officer may issue a certificate releasing the
    property from such lien.