26 USC 6343 - Authority to release levy and return property

(a) Release of levy and notice of release 

(1) In general 
Under regulations prescribed by the Secretary, the Secretary shall release the levy upon all, or part of, the property or rights to property levied upon and shall promptly notify the person upon whom such levy was made (if any) that such levy has been released if
(A) the liability for which such levy was made is satisfied or becomes unenforceable by reason of lapse of time,
(B) release of such levy will facilitate the collection of such liability,
(C) the taxpayer has entered into an agreement under section 6159 to satisfy such liability by means of installment payments, unless such agreement provides otherwise,
(D) the Secretary has determined that such levy is creating an economic hardship due to the financial condition of the taxpayer, or
(E) the fair market value of the property exceeds such liability and release of the levy on a part of such property could be made without hindering the collection of such liability.

For purposes of subparagraph (C), the Secretary is not required to release such levy if such release would jeopardize the secured creditor status of the Secretary.

(2) Expedited determination on certain business property 
In the case of any tangible personal property essential in carrying on the trade or business of the taxpayer, the Secretary shall provide for an expedited determination under paragraph (1) if levy on such tangible personal property would prevent the taxpayer from carrying on such trade or business.
(3) Subsequent levy 
The release of levy on any property under paragraph (1) shall not prevent any subsequent levy on such property.
(b) Return of property 
If the Secretary determines that property has been wrongfully levied upon, it shall be lawful for the Secretary to return
(1) the specific property levied upon,
(2) an amount of money equal to the amount of money levied upon, or
(3) an amount of money equal to the amount of money received by the United States from a sale of such property.

Property may be returned at any time. An amount equal to the amount of money levied upon or received from such sale may be returned at any time before the expiration of 9 months from the date of such levy. For purposes of paragraph (3), if property is declared purchased by the United States at a sale pursuant to section 6335 (e) (relating to manner and conditions of sale), the United States shall be treated as having received an amount of money equal to the minimum price determined pursuant to such section or (if larger) the amount received by the United States from the resale of such property.

(c) Interest 
Interest shall be allowed and paid at the overpayment rate established under section 6621
(1) in a case described in subsection (b)(2), from the date the Secretary receives the money to a date (to be determined by the Secretary) preceding the date of return by not more than 30 days, or
(2) in a case described in subsection (b)(3), from the date of the sale of the property to a date (to be determined by the Secretary) preceding the date of return by not more than 30 days.
(d) Return of property in certain cases 
If
(1) any property has been levied upon, and
(2) the Secretary determines that
(A) the levy on such property was premature or otherwise not in accordance with administrative procedures of the Secretary,
(B) the taxpayer has entered into an agreement under section 6159 to satisfy the tax liability for which the levy was imposed by means of installment payments, unless such agreement provides otherwise,
(C) the return of such property will facilitate the collection of the tax liability, or
(D) with the consent of the taxpayer or the National Taxpayer Advocate, the return of such property would be in the best interests of the taxpayer (as determined by the National Taxpayer Advocate) and the United States,

the provisions of subsection (b) shall apply in the same manner as if such property had been wrongly levied upon, except that no interest shall be allowed under subsection (c).

(e) Release of levy upon agreement that amount is not collectible 
In the case of a levy on the salary or wages payable to or received by the taxpayer, upon agreement with the taxpayer that the tax is not collectible, the Secretary shall release such levy as soon as practicable.