OPINION
Ruwe, Judge:
This case is before the Court on respondent’s motion to dismiss for lack of jurisdiction. Respondent’s motion is based on the ground that the petition was not timely filed. We held a hearing on respondent’s motion during which we raised sua sponte the issue of whether we lack jurisdiction under section 6015(e)1 to review respondent’s denial of equitable relief pursuant to section 6015(f) where no deficiency has been asserted.
The Tax Court may exercise jurisdiction only to the extent authorized by Congress. Fernandez v. Commissioner, 114 T.C. 324, 328 (2000); Gati v. Commissioner, 113 T.C. 132, 133 (1999).2 Whether this Court has jurisdiction is fundamental and may be raised by a party or on the Court’s own motion. Fernandez v. Commissioner, supra at 328; Naftel v. Commissioner, 85 T.C. 527, 530 (1985).
Background
Petitioner and her husband filed a joint tax return for 1995. They reported tax due on their return but did not pay the full amount reported. Respondent has not asserted a deficiency against either petitioner or her husband for 1995.
On February 2, 1999, petitioner filed a Form 8857, Request for Innocent Spouse Relief (And Separation of Liability and Equitable Relief), requesting “equitable relief” for a portion of the amount of the unpaid tax liability shown on the 1995 joint return. On October 31, 2000, respondent mailed a notice of determination concerning relief from joint and several liability under Internal Revenue Code section 6015 (notice of determination). In the notice of determination, respondent listed the type of relief requested as relief under section 6015(b), (c), and (f). Respondent determined that petitioner was entitled to “no relief from tax under section 6015” because petitioner had knowledge of the liability and was still married and living with her husband. The notice of determination was not sent to petitioner’s last known address.
Petitioner filed a petition to this Court pursuant to section 6015(e) seeking review of respondent’s denial of relief from joint and several liability. The petition was received and filed on February 7, 2001, 99 days after the date respondent mailed the notice of determination. The envelope containing the petition was postmarked January 31, 2001, 92 days after the date respondent mailed the notice of determination. The date shown on the petition was January 27, 2001, 88 days after the date respondent mailed the notice of determination.
Discussion
Under present law, there are three primary jurisdictional bases upon which this Court may review a claim for relief from joint and several liability. First, a claim may be raised as an affirmative defense in a petition for redetermination of a deficiency filed pursuant to section 6213(a). Butler v. Commissioner, 114 T.C. 276, 287-288 (2000). A second basis upon which we may exercise jurisdiction is contained in section 6015(e). This provision allows a spouse who has requested relief to petition the Commissioner’s denial of relief, or to petition the Commissioner’s failure to make a timely determination. Such cases are referred to as “stand alone” cases, in that they are independent of any deficiency proceeding. Fernandez v. Commissioner, supra at 329. A third situation where we may exercise jurisdiction to determine relief from joint and several liability is where the issue is properly raised in a collection proceeding under sections 6320 and 6330.3 In the instant case, petitioner’s claim for relief from joint and several liability was made in a “stand alone” petition filed pursuant to section 6015(e).
I. Election Requirement in Section 6015(e)
In Fernandez v. Commissioner, supra at 330, we interpreted the then-existing prefatory language in section 6015(e)(1) — “in the case of an individual who elects to have subsection (b) or (c) apply” — to encompass a procedural requirement applicable to all joint filers seeking relief from joint liability. We noted that section 6015(f) provides an additional opportunity for relief to those taxpayers who do not otherwise meet the requirements of subsection (b) or (c). Fernandez v. Commissioner, supra at 330. Petitioner is seeking relief under section 6015(f). Section 6015(f) permits relief from joint and several liability where “it is inequitable to hold the individual liable for any unpaid tax or any deficiency (or any portion of either)”. (Emphasis added.) Congress did not limit equitable relief under section 6015(f) to situations where a deficiency has been' asserted. H. Conf. Rept. 105-599, at 254-255 (1998), 1998-3 C.B. 747, 1008-1009. However, a prerequisite for relief under section 6015(f) is that relief be unavailable under section 6015(b) or (c), which deals with deficiency situations. Sec. 6015(f)(2); Fernandez v. Commissioner, supra at 330-331. Thus, in every case where the taxpayer submits a request to the Commissioner for relief under section 6015 and such request includes a claim for relief under section 6015(f), the Commissioner must first examine both subsections (b) and (c) to determine whether relief is available under those subsections before determining whether relief is available under section 6015(f). Respondent therefore treated petitioner’s request for relief under section 6015 as an election under section 6015(b), (c), and (f).4
II. Jurisdiction Over Claims Involving Underpayment of Tax
The first issue for decision is whether this Court has jurisdiction under section 6015(e) to review the denial of a request for relief from joint and several liability where no deficiency has been asserted. Both petitioner and respondent agree that we have such jurisdiction.
A. Background of Section 6015
In order to decide this jurisdictional issue, it is necessary to review the evolution of the pertinent statutory provisions and caselaw. Congress enacted section 6015 in 1998 as part of the Internal Revenue Service Restructuring and Reform Act of 1998, Pub. L. 105-206, sec. 3201(a), 112 Stat. 734.5 As originally enacted, section 6015(e) provided, in pertinent part:
SEC. 6015(e). Petition for Review by Tax Court.—
(1) In general. — In the case of an individual who elects to have subsection (b) or (c) apply—
(A) In general. — The individual may petition the Tax Court (and the Tax Court shall have jurisdiction) to determine the appropriate relief available to the individual under this section * * * [Emphasis added.]
Section 6015(f) provides:
SEC. 6015(f). Equitable Relief. — Under procedures prescribed by the Secretary, if—
(1) taking into account all the facts and circumstances, it is inequitable to hold the individual liable for any unpaid tax or any deficiency (or any portion of either); and
(2) relief is not available to such individual under subsection (b) or (c),6
the Secretary may relieve such individual of such liability.
[Emphasis added.]
In two cases decided while the above-quoted statutory language of section 6015(e) was still in effect, we held that this Court had jurisdiction to review denials of requests for relief from joint and several liability pursuant to section 6015(f) in both deficiency and “stand alone” proceedings. In Butler v. Commissioner, 114 T.C. 276 (2000), we addressed the issue of whether we have authority to review a denial of relief under section 6015(f) where a claim for relief from joint and several liability was raised as an affirmative defense in a petition for redetermination of a deficiency filed pursuant to section 6213(a). We interpreted the term “under this section” in section 6015(e)(1)(A) to include all subsections of section 6015. Butler v. Commissioner, supra at 289-290. We found nothing in section 6015(e) that precluded our review of the Commissioner’s denial of equitable relief pursuant to section 6015(f) where the taxpayer makes an election for relief pursuant to section 6015(b) or (c). Id. Additionally, we rejected the Commissioner’s argument that his authority to grant equitable relief is committed to agency discretion because we found that the circumstances allowing action to be committed solely to agency discretion were not present. Id. at 291.
In Fernandez v. Commissioner, supra, we addressed the issue of whether we have authority to review a denial of relief under section 6015(f) where a “stand alone” petition is filed pursuant to section 6015(e). We described section 6015(f) as follows:
Séction 6015(f) provides that the Commissioner may relieve an individual of liability if, taking into account all the facts and circumstances, it is inequitable to hold the individual liable for any unpaid tax or deficiency (or portion thereof) * * * \Id. at 332; emphasis added.]
As we did in Butler v. Commissioner, supra, we expressed the view that Congress intended the term “under this section” in section 6015(e)(1)(A) to include all subsections of section 6015 in their entirety. Fernandez v. Commissioner, supra at 331.7
Our opinions in Fernandez v. Commissioner, supra, and Butler v. Commissioner, supra, examined the legislative history of section 6015 and concluded that it supported our authority to review the application of section 6015(f). Although Fernandez v. Commissioner, supra, and Butler v. Commissioner, supra, both involved deficiencies, we did not limit our holding to deficiency situations or otherwise indicate that this Court lacks jurisdiction in a nondeficiency situation involving a claim for relief from liability for an underpayment of tax shown on a joint return. As we pointed out in Butler v. Commissioner, supra at 290, the House report states that “The bill specifically provides that the Tax Court has jurisdiction to review any denial (or failure to rule) by the Secretary regarding an application for innocent spouse relief”, and the Senate report provides th|tt?“The Tax Court has jurisdiction of disputes arising from the separate liability election.” The proposed Senate amendment applied the separate liability election to situations involving deficiency determinations and situations where the tax shown on the return was not paid with the return. S. Rept. 105-174, at 57-58 (1998), 1998-3 C.B. 537, 593-55)4. The Senate amendment clearly provided for Tax Court review in situations involving both deficiencies and underpayments of tax shown on the return. Id. at 56, 1998-3 C.B. at 592. The Senate amendment also added an “Equitable Relief” provision similar to what is now contained in section 6015(f), providing equitable relief “for any unpaid tax or any deficiency5. 144 Cong. Rec. S4577 (daily ed. May 8, 1998). The Senate amendment also provided for Tax Court jurisdiction “In the case of an individual who elects to have this section [section 6015] apply”. Id. The conference agreement did not include the portion of the Senate amendment applying the separate liability election in situations where the tax shown on the return was not paid with the return. However, the conference agreement added section 6015(f) which, like the Senate amendment, allows equitable relief for unpaid tax shown on the return. H. Conf. Rept. 105-599, supra at 254, 1998-3 C.B. 755, 1008. The conference agreement followed the Senate amendment in establishing Tax Court jurisdiction in this area. Id.
The following language contained in the conference report supports our view that, in enacting section 6015, Congress intended for this Court to have jurisdiction over situations involving any claim for relief from joint and several liability, including nondeficiency situations where an individual is seeking relief only for an underpayment of tax shown on a joint return:
The conference agreement follows the Senate amendment with respect to deficiencies of a taxpayer who is no longer married to, is legally separated from, or has been living apart for at least 12 months from the person with whom the taxpayer originally filed the joint return. The conference agreement also includes the provision in the House bill expanding the circumstances in which innocent spouse relief is available. Taxpayers, whether or not eligible to make the separate liability election, may be granted innocent spouse relief where appropriate. In addition, the conference agreement authorizes the Secretary to provide equitable relief in appropriate situations. The conference agreement follows the House bill and the Senate amendment in establishing jurisdiction in the Tax Court over disputes arising in this area. [H. Conf. Rept. 105-599, supra at 251, 1998-3 C.B. at 1005; emphasis added.]
The language in the conference report indicates that the reference to disputes arising in “this area” was intended to encompass claims for relief arising under section 6015(b), (c), and (f). The reference to our jurisdiction comes directly after the conference report discusses the Senate amendment (relating to section 6015(c)), the House bill (relating to section 6015(b)), and the conference agreement’s new provision authorizing equitable relief in appropriate situations (relating to section 6015(f)). The conference report then states that it follows the House bill and Senate amendment in establishing jurisdiction in this Court over disputes arising in “this area”.8 Additionally, the conference report provides that “The conference agreement follows the House Bill and the Senate amendment with respect to procedural rules, including the jurisdiction of the Tax Court to review matters relating to this provision” H. Conf. Rept. 105-599, supra at 255, 1998-3 C.B. at 1009 (emphasis added). The references to “this area” and “this provision” reflect Congress’s intent that our jurisdiction extend to claims arising under all three subsections of section 6015, including claims for relief in nondefi-ciency situations. Had Congress intended to limit our jurisdiction to deficiency situations only, presumably it would not have used such broad terms as “this area” and “this provision” to describe the scope of our authority to review claims for relief from joint and several liability. See, e.g., Fernandez v. Commissioner, 114 T.C. at 331 (interpreting reference to “this section” in section 6015(e)(1)(A) to encompass all subsections of section 6015); Butler v. Commissioner, 114 T.C. at 290 (same); Woodral v. Commissioner, 112 T.C. 19, 22-23 (1999) (interpreting reference to “this section” in section 6404(g) to encompass all subsections of section 6404). Accordingly, we conclude that, in enacting section 6015, Congress did not intend to limit our authority to review claims for relief from joint and several liability to deficiency situations.
B. Amendment of Section 6015(e)
Subsequent to our opinions in Fernandez v. Commissioner, supra, and Butler v. Commissioner, supra, Congress amended section 6015(e) effective on December 21, 2000. Consolidated Appropriations Act, 2001 (Consolidated Appropriations Act, 2001), Pub. L. 106-554, app. G, sec. 313, 114 Stat. 2763A-641 (2000). As a result, section 6015(e) currently provides, in pertinent part:
SEC. 6015(e). Petition for Review by Tax Court.—
(1) In general. — In the case of an individual against whom, a deficiency has been asserted and who elects to have subsection (b) or (c) apply—
(A) In general. — In addition to any other remedy provided by law, the individual may petition the Tax Court (and the Tax Court shall have jurisdiction) to determine the appropriate relief available to the individual under this section * * *
[Emphasis added.]
The petition in the instant case was filed after the effective date of this provision. The issue we must decide is whether the amendment to section 6015(e) by the Consolidated Appropriations Act, 2001, presents a new requirement that a deficiency must be asserted before this Court has jurisdiction to review respondent’s denial of equitable relief pursuant to section 6015(f) in a “stand alone” proceeding.
In interpreting section 6015(e), our purpose is to give effect to Congress’s intent. Fernandez v. Commissioner, supra at 329. We begin with the statutory language, and we interpret that language with reference to the legislative history primarily to learn the purpose of the statute and to resolve any ambiguity in the words contained in the language. Allen v. Commissioner, 118 T.C. 1, 7 (2002) (and cases cited therein). Usually, the plain meaning of the statutory language is conclusive. United States v. Ron Pair Enters., Inc., 489 U.S. 235, 242 (1989); Woodral v. Commissioner, supra at 23. If the statute is ambiguous or silent, we may look to the statute’s legislative history to determine congressional intent. Burlington N. R.R. v. Okla. Tax Commn., 481 U.S. 454, 461 (1987); Fernandez v. Commissioner, supra at 329-330. Finally, because the changes to the relief from joint and several liability rules “were designed to correct perceived deficiencies and inequities in the prior version” of the rules, this curative legislation should be construed liberally to effectuate its remedial purpose. Flores v. United States, 51 Fed. Cl. 49, 53 (2001) (citing Tcherepnin v. Knight, 389 U.S. 332, 336 (1967); Piedmont & N. Ry. Co. v. ICC, 286 U.S. 299, 311-312 (1932)).
Our interpretation of section 6015(e) concerns the new language “against whom a deficiency has been asserted”. However, section 6015(e)(1)(A) still contains the provision giving this Court jurisdiction “to determine the appropriate relief available to the individual under this section” (emphasis added), which, as previously explained, we have held gives us jurisdiction over the propriety of equitable relief under section 6015(f). Equitable relief under section 6015(f) is, and always has been, available in nondeficiency situations. Under these circumstances, the amendment to section 6015(e)(1) referring to situations where “a deficiency has been asserted” and the retention of the language in that same section giving us jurisdiction over “the appropriate relief available to the individual under this section” creates an ambiguity. Therefore, it is appropriate to consult the legislative history of the amendment made by the Consolidated Appropriations Act, 2001.
The conference report accompanying the Consolidated Appropriations Act, 2001 provides the following discussion regarding the amendment of section 6015(e):
Timing of request for relief. — Confusion currently exists as to the appropriate point at which a request for innocent spouse relief should be made by the taxpayer and considered by the IRS. Some have read the statute to prohibit consideration by the IRS of requests for relief until after an assessment has been made, i.e., after the examination has been concluded, and if challenged, judicially determined. Others have read the statute to permit claims for relief from deficiencies to be made upon the filing of the return before any preliminary determination as to whether a deficiency exists or whether the return will be examined. The consideration of innocent spouse relief requires that the IRS focus on the particular items causing a deficiency; until such items are identified, the IRS cannot consider these claims. Congress did not intend that taxpayers be prohibited from seeking innocent spouse relief until after an assessment has been made; Congress intended the proper time to raise and have the IRS consider a claim to be at the same point where a deficiency is being considered and asserted by the IRS. This is the least disruptive for both the taxpayer and the IRS since it allows both to focus on the innocent spouse issue while also focusing on the items that might cause a deficiency. It also permits every issue, including the innocent spouse issue, to be resolved in single administrative and judicial process. The bill clarifies the intended time by permitting the election under (b) and (c) to be made at any point after a deficiency has been asserted by the IRS. A deficiency is considered to have been asserted by the IRS at the time the IRS states that additional taxes may be owed. Most commonly, this occurs during the Examination process. It does not require an assessment to have been made, nor does it require the exhaustion of administrative remedies in order for a taxpayer to be permitted to request innocent spouse relief. * * * [H. Conf. Rept. 106-1033, at 1023 (2000); see also Vetrano v. Commissioner, 116 T.C. 272, 279 (2001).]
The conference report indicates that the language “against whom a deficiency has been asserted” was inserted into section 6015(e) to clarify the proper time for making a request to the Commissioner for relief from joint and several liability for tax that may have been underreported on the return. Congress wanted to prevent taxpayers from submitting premature requests to the Commissioner for relief from potential deficiencies before the Commissioner had asserted that additional taxes were owed. Congress also wanted to make it clear that a taxpayer does not have to wait until after an assessment has been made before submitting a request to the Commissioner for relief under section 6015. -Overall, the legislative history indicates that Congress was concerned with the proper timing of a request for relief for under-reported tax and intended that taxpayers not be allowed to submit a request to the Commissioner regarding under-reported tax until after the issue was raised by the IRS.9
There is nothing in the legislative history indicating that the amendment of section 6015(e) by the Consolidated Appropriations Act, 2001, was intended to eliminate our jurisdiction regarding claims for equitable relief under section 6015(f) over which we previously had jurisdiction. The stated purpose for inserting the language “against whom a deficiency has been asserted” into section 6015(e) was to clarify the proper time for a taxpayer to submit a request to the Commissioner for relief under section 6015 regarding under-reported taxes.10 We conclude that the amendment of section 6015(e) does not preclude our jurisdiction to review the denial of equitable relief under section 6015(f) where a deficiency has not been asserted.
In the instant case, petitioner filed a claim for relief from joint and several liability for an amount of tax correctly shown on the return but not paid with the return. Because respondent has not challenged the tax reported on the return, no deficiency has been asserted. In this situation, petitioner may be entitled to relief under section 6015(f) because subsection (f) applies where “it is inequitable to hold the individual liable for any unpaid tax or any deficiency”.11 Sec. 6015(f) (emphasis added); Fernandez v. Commissioner, 114 T.C. at 332; H. Conf. Rept. 105-599, supra at 254-255, 1998-3 C.B. at 1008-1009; Rev. Proc. 2000-15, 2000-5 I.R.B. 447; see also Smith v. Commissioner, T.C. Memo. 2001-313.12 Because the tax was reported on the return, respondent need not issue a notice of deficiency in order to assess the tax. Bresson v. Commissioner, 111 T.C. 172 (1998), affd. 213 F.3d 1173 (9th Cir. 2000). Respondent and petitioner are both aware that petitioner has an unpaid tax liability which is due. In this situation, Congress’s concern, premature requests for relief, is not present because there is no dispute over the amount of tax required to be shown on the return.
C. Conclusion
Both parties agree that petitioner is jointly and severally liable for the unpaid tax unless she is entitled to equitable relief under section 6015(f). Respondent has treated the request as an election under section 6015(b), (c), and (f). Both parties agree that the absence of a deficiency is no impediment to our jurisdiction in the instant case. After examining section 6015 as originally enacted, the subsequent amendment by the Consolidated Appropriations Act, 2001, the legislative history, and relevant caselaw, we agree with the parties and hold that the absence of an asserted deficiency does not deprive us of jurisdiction over petitioner’s claim for equitable relief pursuant to section 6015(f).
III. Timeliness of Petition
The next issue is whether the petition was timely filed under section 6015(e). Section 6015(e)(1)(A) provides, in pertinent part, that an individual may file a petition:
(i) at any time after the earlier of—
(I) the date the Secretary mails, by certified or registered mail to the taxpayer’s last known address, notice of the Secretary’s final determination of relief available to the individual, or
(II) the date which is 6 months after the date such election is filed with the Secretary, and
(ii) not later than the close of the 90th day after the date described in clause (i)(I).c[13]
In the instant case, the petition was filed more than 6 months after the date petitioner submitted to respondent her request for relief under section 6015. The notice of determination was not mailed to petitioner’s last known address. Thus, the petition was not filed later than the close of the 90th day after the date respondent mailed the notice of determination to petitioner’s last known address. While this would seem to end the matter, respondent argues that petitioner received the notice in sufficient time to file a timely petition within 90 days and that somehow we should therefore find that the petition was filed after the 90-day period described in section 6015(e)(l)(A)(ii).
Respondent relies on the fact that the petition is dated 2 days before the 90th day after respondent mailed the notice of determination. Respondent points out that the petition would have been timely if mailed on the date shown on the petition. Respondent notes that cases involving a notice of deficiency have recognized that actual receipt of the notice without prejudicial delay is sufficient for the notice to be effective even though not sent to the taxpayer’s last known address. Assuming that this rationale could have some application in deciding when the 90-day period referred to in section 6015(e)(l)(A)(ii) begins, we find that the improperly addressed notice did result in prejudicial delay.
In a deficiency proceeding, our jurisdiction depends on the issuance of a valid notice of deficiency and a timely filed petition. Rule 13(a), (c); Monge v. Commissioner, 93 T.C. 22, 27 (1989). Section 6212(a) authorizes the Commissioner to send a notice of deficiency to a taxpayer by certified mail or registered mail. The taxpayer must generally file a petition to this Court within 90 days after the date the notice of deficiency is mailed. Sec. 6213(a). Section 6212(b)(1) provides that it “shall be sufficient” for jurisdictional purposes if the Commissioner mails the notice of deficiency to the taxpayer at the taxpayer’s last known address. Frieling v. Commissioner, 81 T.C. 42, 52 (1983). It is well settled that, although a deficiency notice properly mailed to a taxpayer’s last known address provides the Commissioner with a “safe harbor” under section 6212(b), an improperly addressed notice of deficiency remains valid under section 6212(a) if it is actually received in sufficient time to permit the taxpayer to file a timely petition for redetermination. Mulvania v. Commissioner, 81 T.C. 65, 67-69 (1983), affd. 769 F.2d 1376 (9th Cir. 1985).
The determination of whether a taxpayer’s ability to file a timely petition has been prejudiced by an improperly addressed notice is factual in nature. Looper v. Commissioner, 73 T.C. 690, 699 (1980). In general, the cases in which we have held that an improperly addressed notice of deficiency was actually received with sufficient time to permit the taxpayer to file a timely petition for redetermination have involved receipt with at least 30 days left in the filing period. See, e.g., Mulvania v. Commissioner, supra at 68 (74 days remaining); Bowers v. Commissioner, T.C. Memo. 1991-609 (69 days remaining); Fileff v. Commissioner, T.C. Memo. 1990-452 (60 days remaining); George v. Commissioner, T.C. Memo. 1990-147 (52 days remaining); Bulakites v. Commissioner, T.C. Memo. 1998-256 (45 days remaining); Loftin v. Commissioner, T.C. Memo. 1986-322 (30 days remaining); Eger v. Commissioner, T.C. Memo. 1984 — 325 (30 days remaining). In a situation where a notice was actually received with only 17 days left in the filing period, we held that the taxpayer was prejudiced by the improperly addressed notice because he did not let the notice languish and “he took responsible steps in an attempt to fulfill requisites to contest the Commissioner’s determination in the Tax Court.” Looper v. Commissioner, supra at 699.
Applying this standard in the context of a notice of determination under section 6015,14 we find that petitioner’s ability to timely file the petition was prejudiced by the improperly addressed notice. At the hearing, petitioner stated that during the relevant period she was busy attending to her injured husband and did not know when she received the notice of determination. The only evidence of a specific date shows that the notice was received by January 27, 2001, which was the date written on the petition.15 This date, upon which respondent relies, was 88 days after respondent mailed the notice of determination and only 2 days prior to the last day for filing a petition.
Petitioner initiated and has diligently pursued relief from joint liability. There is no evidence that petitioner let the notice languish or otherwise failed to take responsible steps to contest respondent’s determination in this Court. Therefore, on the basis of the evidence in the record, we find that the delay caused by the improperly addressed notice was prejudicial to petitioner’s ability to timely, by January 29, 2001, file her petition.
IV. Conclusion
We hold that the petition in the instant case was timely under section 6015(e)(1)(A) and that we have jurisdiction to determine the appropriate relief available to petitioner under section 6015(f) for the underpayment of tax shown on petitioner’s joint return.
An appropriate order will be issued denying respondent’s motion to dismiss for lack of jurisdiction.
Reviewed by the Court.
Wells, Cohen, Swift, Gerber, Halpern, Beghe, Chiechi, and Gale, JJ., agree with this majority opinion. Thornton, J., dissents.