42 U.S. Code § 1490h. Taxation of property held by Secretary
All property subject to a lien held by the United States or the title to which is acquired or held by the Secretary under this subchapter other than property used for administrative purposes shall be subject to taxation by a State, Commonwealth, territory, possession, district, and local political subdivisions in the same manner and to the same extent as other property is taxed: Provided, That no tax shall be imposed or collected on or with respect to any instrument if the tax is based on—
the value of any property conveyed or transferred to the Secretary, whether as a tax on the instrument, the privilege of conveying or transferring, or the recordation thereof; nor shall the failure to pay or collect any such tax be a ground for refusal to record or file such instruments, or for failure to impart notice, or prevent the enforcement of its provisions in any State or Federal court.
Refund of Tax Payments Prior to October 12, 1977, Barred; Federal Officers or Employees Not Liable for Such Payments
“Notwithstanding any other provision of law, no State, Commonwealth, territory, possession, district, or local political subdivision which has received, prior to the date of enactment of this Act [Oct. 12, 1977], tax payments from the Department of Agriculture based on property held by the Farmers Home Administration shall be liable for, or be obligated to refund, the amount of any such payment, which, if it had been made after the date of enactment of this Act, would have been authorized by the provisions of section 528 of the Housing Act of 1949 [this section], and no officer or employee of the United States shall incur or be under any liability by reason of having made or authorized any such payments.”