This case presents a narrow question about the scope of a valid federal tax lien on property the taxpayer held in joint tenancy, when the lien attaches (and is recorded) prior to the taxpayer’s death, but the Internal Revenue Service forecloses on the lien some two years later. Mrs. Carole Librizzi, an innocent spouse, argues that the Government may recover no more than one-half the value of the property at the time of her husband’s death, while the United States asserts that once the lien attached to the property, it may recover one-half the amount the property fetches at the foreclosure sale. Although the district court ruled for Mrs. Librizzi, we con-*137elude that the United States has the better of the argument, and we therefore reverse.
The underlying facts are undisputed. In 1975, Salvadore Librizzi (the taxpayer) and his wife Carole acquired real property located at 307 East Carlisle Avenue, Whitefish Bay, Wisconsin, which they held under Wisconsin law as joint tenants with a right of survivorship. A decade later, in 1985 and 1986, the Secretary of the Treasury made a number of tax assessments totaling $1,468,-312.72 against Mr. Librizzi relating to wagering activities and associated interest and penalties. When Mr. Librizzi did not pay the amounts due, a federal tax lien arose pursuant to 26 U.S.C. § 6321, and attached to all property belonging to him. On September 26,1986, and on December 15,1989, the IRS filed Notices of Federal Tax Lien for Mr. Librizzi’s assessed liabilities with the Register of Deeds, Milwaukee County, Wisconsin. Mr. Librizzi died on June 19, 1990, without having paid his taxes.
Upon her husband's death, Mrs. Librizzi took full title to the Carlisle Avenue property. Two years later, on October 6, 1992, the United States filed a suit for foreclosure of its liens under 26 U.S.C. § 7403 in the U.S. District Court for the Eastern District of Wisconsin. In that suit, Mrs. Librizzi conceded that the federal tax lien attached to Mr. Librizzi's one-half interest in the property and that when he died she acquired the property subject to that lien. She argued, however, that the Government's interest was limited to one-half of the estimated fair market value of the property at the time of Mr. Librizzi's death (that is, one-half of $152,500, or $76,250). This was an attractive position for her to take, because the property had appreciated in value during the time between his death and the suit: as of the time of suit, it was estimated to be worth some $173,100. The Government took the position that it was entitled to one-hail the fair market value at the time of foreclosure, which would have yielded about $86,550-still considerably less than the amount due for the delinquent taxes. As noted above, the district court, rely-iiig on provisions of Wisconsin law we discuss below, granted summary judgment for Mrs. Librizzi, and the United States has appealed.
When dealing with tax liens under 26 U.S.C. § 6321, it has been settled for years that “state law controls in determining the nature of the legal interest which the taxpayer had in the property.” United States v. National Bank of Commerce, 472 U.S. 713, 722, 105 S.Ct. 2919, 2925, 86 L.Ed.2d 565 (1985) (citations and internal quotation marks omitted). See also United States v. Rodgers, 461 U.S. 677, 683, 103 S.Ct. 2132, 2137, 76 L.Ed.2d 236 (1983). The federal tax lien attaches to whatever rights or interests the taxpayer has under state law. National Bank of Commerce, 472 U.S. at 722, 105 S.Ct. at 2925; Rodgers, 461 U.S. at 683, 103 S.Ct. at 2137. As the Wisconsin Supreme Court put it:
... the I.R.C. does not create any property rights, but merely attaches federally defined consequences to rights which are created under state law. Once state law has been used to determine the nature and existence of a property interest, further state law is inoperative, and the tax consequences thenceforth are dictated by federal law.
Elfelt v. Cooper, 168 Wis.2d 1008, 485 N.W.2d 56, 61 (1992) (citations omitted). Furthermore, the U.S. Supreme Court noted in Rodgers that “once a lien has attached to an interest in property, the lien cannot be extinguished (assuming proper filing and the like) simply by a transfer or conveyance of the interest.” 461 U.S. at 691 n. 16, 103 S.Ct. at 2141 n. 16.
A federal tax lien attaches at the time the tax assessment is made, and it continues until the liability has been satisfied or it becomes unenforceable due to the lapse of time. 26 U.S.C. § 6322. See also Jersey State Bank v. United States, 926 F.2d 621, 622-23 (7th Cir.1991); J.D. Court, Inc. v. United States, 712 F.2d 258, 261 & n. 7 (7th Cir.1983). In this case, it is undisputed that the tax lien attached to Mr. Librizzi’s undivided one-half interest in the Carlisle Avenue property in 1985 and 1986, at the time the assessments were made. Mrs. Librizzi argues, however, that the character of the lien changed at the time of Mr. Librizzi’s death, when under the Wisconsin law of joint tenancy, Mrs. Librizzi became the sole owner of *138the property. Wis. Stat. Ann. § 700.17(2)(a). At that point, she claims, the lien changed from an encumbrance on the interest in the property to an I.O.U. for the value of Mr. Librizzi’s interest in the property on the date of his death. She relies principally on language in the Third Circuit’s decision in United States v. Avila, 88 F.3d 229 (3d Cir.1996), but also on the Wisconsin Supreme Court’s early decision in Musa v. Segelke & Kohlhaus Co., 224 Wis. 432, 272 N.W. 657 (1937), to support this position.
In Musa, the Wisconsin Supreme Court considered the effect of a judgment lien on property held in joint tenancy, after the joint tenant who was the judgment debtor died. The judgment lien there had been docketed, but not executed, on the date of the debtor’s death. The supreme court decided that “the lien of the judgment in question could attach only to such interest or estate as Adam Musa [the debtor] actually and effectively had in the premises.” Id., 272 N.W. at 658. Because his interest was only that of a joint tenant, it was limited by the right of surviv-orship. Upon his death, when the property passed to the other joint tenant, the judgment lien itself was extinguished: there was no more property of the debtor on which the Ken could operate. Mrs. Librizzi does not take her argument as far as Musa might suggest, as she does not contend that the tax Kens vanished when Mr. Librizzi died. She does say, however, that Musa means that the Ken attached only to the interest Mr. Librizzi had while akve, and that this interest was finaKy determined as of the moment of his death.
Later legislation and court decisions in Wisconsin indicate that the Musa rule does not have the consequences Mrs. Librizzi claims for it. Section 700.24 of the Wisconsin Statutes addresses the effect of a joint tenant’s death on certain Kens (including, we note, state tax Kens attached pursuant to Wisconsin law):
A real estate mortgage, a security interest under ch. 409, or a Ken under s. 71.91(5)(b), s. 72.86(2), 1985 stats., ch. 49 or 779 on or against the interest of a joint tenant does not defeat the right of surviv-orship in the event of the death of such joint tenant, but the surviving joint tenant or tenants take the interest such deceased joint tenant could have transferred prior to death subject to such mortgage, security interest or statutory Ken.
Mr. Librizzi could have transferred his undivided one-half interest to Mrs. Librizzi before his death, by taking steps to sever the joint tenancy and then to convey his interest to her. In that case, the federal tax Ken would have- continued to encumber his one-half interest in her hands. See, e.g., United States v. Bess, 357 U.S. 51, 57, 78 S.Ct. 1054, 1058, 2 L.Ed.2d 1135 (1958) (“The transfer of property subsequent to the attachment of the Ken does not affect the Ken[.]”). The effect of § 700.24 is to make it clear that the same result foUows even if he did not go through those steps during his lifetime. When the undivided one-half interest passed to Mrs. Librizzi by operation of law, it came encumbered with the federal tax Ken.
Taking another approach, Mrs. Librizzi points to Avila, in which the Third Circuit held that the Government could recover on a tax Ken imposed on a husband’s one-half interest in a joint tenancy, even though the property had later been transferred to his wife (first for a payment of $100, and later in a divorce settlement). There, as here, the district court had held that the Government could recover only the amount that the Ken was worth at the time the debtor transferred his interest to his wife. Citing the Ninth Circuit’s decision in Han v. United States, 944 F.2d 526 (9th Cir.1991), the court reversed, holding that “because the Ken is unaffected by sale, we see no basis for fixing the amount of the Ken at the time of sale.” Avila, 88 F.3d at 233 (internal quotations omitted). The Ken continued to attach to the debtor’s entire former interest in the property, limited only by the amount of the debt it secured and a third party’s right to equitable subrogation (a compKcation not present in Mrs. Librizzi’s ease).
So far, Avila provides more support for the Government’s position than the reverse, but Mrs. Librizzi reKes on one additional part of the Avila decision to support her claim for a limitation on value. Similar to the Wisconsin court in Musa, the Third Cir*139cuit stated that if the debtor predeceased his wife, then the lien would be extinguished. Id. at 236. This conclusion resulted from the court’s analysis of New Jersey law, which did not include anything like Wis. Stat. Ann. § 700.24. As we hinted earlier, we think the “extinguishment” argument for purposes of the present case proves either too much or too little. If Mr. Librizzi’s death truly extinguished the lien, then the Government would be entitled to nothing, not to the value of the debtor’s interest at the time of his death. The state statute rules out this possibility, however. In a later case construing both the statute and Musa, the Wisconsin Supreme Court recognized that the rule for judgment liens is different from the rule for the types of liens mentioned in § 700.24. See Northern State Bank v. Toal, 69 Wis.2d 50, 230 N.W.2d 153, 156 (1975) (judgment liens must be executed before the debtor’s death in order to sever the joint tenancy and avoid being extinguished by the spouse’s right of survivor-ship). Liens covered by the statute are unlike unexecuted judgment liens because they remain in force against the surviving joint tenant. See John E. Talsky, Comment, Concurrent Ownership: Joint Tenancy & Tenancy In Common Under Chapter 700, 55 Marq. L.Rev. 321, 345 (1972) (noting that under Wis. Stat. Ann. § 700.24, tax liens imposed under Wis. Stat. Ann. § 71.91 remain attached to the property even after the debtor spouse’s death).
Finally, nothing in Musa or Avila supports the rather odd notion that the lien survived Mr. Librizzi’s death, but became frozen in value as of the date of his death. The Government notes that such a rule might be unwelcome to an innocent spouse if the value of the property had declined after the date of death, since in that event she would be required to pay more than one-half the fair market value at sale. But we do not need to explore this possibility further, other than to note that the rule we adopt is not systematically biased either for or against the taxpayer. Under Wisconsin law, the tax lien ran against Mr. Librizzi’s undivided one-half interest. If the Government had enforced its lien during his lifetime, it could have compelled a severance of the property and Mrs. Librizzi would have received only her one-half interest (plus an $21,719.25 which she paid to retire the balance of the mortgage). Wisconsin law gives her no more interest in the estate she received through the joint tenancy rule of sur-vivorship than she would have had if Mr. Librizzi had lived.
We therefore Reverse the judgment below and Remand for further proceedings consistent with this opinion.