delivered the opinion of the Court.
On his 1979 income tax return, petitioner, a shareholder in a Subchapter S corporation, claimed as “pass-through” items portions of a deduction and a tax credit reported on the corporation’s return. The question presented is whether the 3-year period in which the Internal Revenue Service is permitted to assess petitioner’s tax liability runs from the filing dаte of the individual return or the corporate return. We conclude with the Tax Court and the Court of Appeals for the Second Circuit that the relevant date is that on which petitioner’s return was filed.
I
Subchapter S of the Internal Revenue Code, 26 U. S. C. §§ 1361-1379, was enacted in 1958 to eliminate tax disadvantages that might dissuade small businesses from adopting *525 the corporate fоrm and to lessen the tax burden on such businesses. The statute accomplishes these goals by means of a pass-through system under which corporate income, losses, deductions, and credits are attributed to individual shareholders in a manner akin to the tax treatment of partnerships. See §§ 1366-1368. 1 In addition, since 1966, “S corporations” have been liable for certаin capital gains and other taxes. 80 Stat. 111, 113; 26 U. S. C. §§ 1374, 1378.
Petitioner was treasurer and a shareholder of Compo Financial Services, Inc., an S corporation. On February 1, 1980, Compo filed a return for the tax year of December 26, 1978, to November 30, 1979, as required by § 6037(a) of the Code. 2 On that return, Compo reported a loss deduction and an investment tax credit arising from its partnеrship interest in a venture known as Printers Associates. Petitioner and his wife filed a joint return for 1979 on April 15, 1980. 3 Their return claimed a pro rata share of the deduction and credit reported by Compo pursuant to the pass-through provisions of Subchapter S.
Code § 6501(a) establishes a generally applicable statute of limitations providing that the Internal Revenue Service may assess tax deficiencies within a 3-year period from the date *526 a return is filed. 4 That limitations period may be extended by written agreement. § 6501(c)(4). In March 1983, before three years had passed from the time the joint return was filed, petitioner agreed to extend the period in which deficiencies arising from certain claims on the return could be assessed against him. No extension was obtained from Compo with respect to its return for the 1978-1979 tax year.
In 1987, the Commissioner determined that the loss deduction and credit reported by Compo were erroneous and sent a notice of deficiency to petitioner based on the loss deduction and credit that he had claimed on his return. In the Tax Court, petitioner contended thаt the Commissioner’s claim was time barred because the disallowance was based on an error in Compo’s return, for which the 3-year assessment period had lapsed. The Tax Court found for the Commissioner, relying on its decision in
Fehlhaber
v.
Commissioner,
II
Title 26 U. S. C. § 6501(a) states simply that “the amount of any tax imposed by this title shall be assessed within 3 *527 years after the return was filed . . . The issue before us is whether “the” return is that of petitioner or that of thе corporation which was the source of the loss and credit claimed on petitioner’s return. Petitioner’s position is that the Commissioner had three years from the date his return was filed to object to that return in any respect except the loss and credit items passed through to him by the corporation. To disallow those items, petitioner argues, the Commissioner must have acted within three years of the filing of the corporate return. Under this approach, “the” return referred to in § 6501(a) becomes two returns, and petitioner claims that there is adequate statutory basis for his submission. We have no doubt that the courts below properly concluded, as the Commissioner argued, that it is the filing of petitioner’s return that triggers the running of the statutory period.
The Commissioner can only determine whether the taxpayer understated his tax obligation and should be assessed a deficiency after examining that taxpayer’s return. Plainly, then, “the” return referred to in § 6501(a) is the return of the taxpayer against whom a deficiency is assessed. Here, the Commissioner sought to assess taxes which petitioner оwed under the Code because his return had erroneously reported a loss and credit to which he was not entitled. The fact that the corporation’s return erroneously asserted a loss and credit to be passed through to its shareholders is of no consequence. In this case, the errors on the corporate return did not and could not affect the tax liability of the corporation, and hence the Commissioner could only assess a deficiency against the stockholder-taxpayer whose return claimed the benefit of the errors. Under the plain language of § 6501(a), the Commissioner’s time to make the assessment ran from the filing date of petitioner’s return. 6
*528 By contrast, the S corporation’s return, which petitioner asserts triggers the beginning of the limitations period, is deficient precisely because it does not contain all of the information necessary to compute a shareholder’s taxes. If the Internal Revenue Service were required to rely on that return, it would be forced to conduct its assessment on the basis of incomplete information:
“While [the corporate return] may show petitioner’s distributive share of losses, it does not indicate his adjusted basis in his corporate stock, which is information necessary to determine if the loss is deductible. Nor does it show petitioner’s income, losses, deductions, and credits from other sources. Moreover, the information return of the S corporation does not rеlate to the same taxable period as petitioner’s return . . . .” Fehlhaber, supra, at 869 (citation omitted).
As noted in analogous cases, tax returns that “lack the data necessary for the computation and assessment of deficiencies” generally should not be regarded as triggering the period of assessment.
Automobile Club of Mich.
v.
Commissioner,
Petitioner asserts that § 6501(a) supports a contrary view when read in light of two relatеd Code provisions pertaining *529 to S corporations. Section 6012(a)(2) requires both Sub-chapter C and Subchapter S corporations to file income tax returns. 8 Section 6037(a) specifies the information that each S corporation’s return must provide (including “each shareholder’s pro rata share of each item of the corporation”) and further states that “[a]ny return filed pursuant to this section shall, for purposes of [26 U. S. C. §§6501-6531], be treated as a return filed by the corporation under section 6012.”
We do not see that these provisions aid petitioner’s cause. Read together, §§ 6012(a)(2), 6037(a), and 6501(a) establish only that each S corporation must file a tax return containing certain information and that a Commissiоner desiring to make an assessment must act within three years of filing. Nothing on the face of these provisions demonstrates that an individual’s income tax return is brought within the compass of § 6037(a)’s reference to “any return” simply because a portion of that return reports income and losses that have passed through from the return of an S corporation. If anything, the рhrase “[a]ny return filed pursuant to this section,” coupled with the fact that § 6037(a) is concerned with describing the contents of the corporation’s return, indicates that the provision is not meant to determine when the assessment period for a shareholder’s individual tax return begins.
Petitioner argues that this reading of the relevant provisions runs afoul of the fact that, prior tо 1966, S corporations were not subject to taxation. According to petitioner, no purpose would have been served by establishing an assessment period that applied to returns reporting corporate income on which no taxes could be assessed but not to the
*530
returns of corporate stockholders. This argument fails because evеn in the period when the S corporation could net be taxed, examination of a corporation’s return was necessary to determine if it could lay valid claim to Subchapter S status. Section 6037(a) thus originally functioned to set the starting date of the 3-year period within which that determination had to be made. See
United States
v.
Adams Building Co.,
*531
The Ninth Circuit’s rejection in
Kelley
v.
Commissioner,
“First, it is not unfamiliar in the world of tаx to have ‘an individual’s income tax return ... dependent on records maintained by another entity.’ Fehlkaber,954 F. 2d at 658 (citing partnership and trust taxation as examples). Second, the rule generally does not impose an undue burden on the corporation or the shareholder. ... A shareholder can ‘take the necessary steps to ensure that the corporation preserves the relevant records.’ Id. Such protective steps simply do not constitute an overly oppressive task for the shareholder. Bufferd,952 F. 2d at 678 . . . . Finally, we reject any suggestion that we elevate the ‘perceived unfairness to taxpayers’ over our duty to strictly construe in favor of the government a statute of limitation when the petitioner seeks appliсation of the statute so as to bar the rights of the government. Fehlkaber,954 F. 2d at 658 .” Id., at 789. 11
*533 H-( H-(
As found by the courts below, the plain language of § 6501(a) supports the Commissioner. The statutory evidence and policy considerations proffered by petitioner offer no basis for questioning this conclusion. We hold that the limitations period within which the Internal Revenue Service must assess the income tax liability of an S corporation shareholder runs from the date on which the shareholder’s return is filed. The judgment of the Court of Appeals is affirmed.
It is so ordered.
Notes
Subchapter S was substantially amended and recodified by the Sub-chapter S Revision Act of 1982, 96 Stat. 1669. The pass-through provisions in effect in the period relevant to this case, see 26 U. S. C. §§ 1373-1374 (1976 ed.), differ in certain respects from the рresent provisions. These differences do not affect the case.
In relevant part, the statute reads:
“§ 6037. Return of S corporation
“(a) In general
“Every S corporation shall make a return for each taxable year, stating specifically the items of its gross income and the deductions allowable by subtitle A [and other information]. Any return filed pursuant to this section shall, for purposes of chapter 66 (relating to limitations), be treatеd as a return filed by the corporation under section 6012.”
Phyllis Bufferd settled separately with the Commissioner and is not a party to this action.
The statute reads in part:
“§ 6601. Limitations on assessment and collection
“(a) General rule
“Except as otherwise provided . . . the amount of any tax imposed by this title shall be assessed within 3 years after the return was filed ...
Kelley
v.
Commissioner,
Even if it could credibly be argued that § 6501(a) is ambiguous because it does not expressly indicate how it is to be applied to S corporations and their stockholders, the Commissioner’s construction of the section is
*528
a reasonable one to say the least, and we should accept it absent convincing grounds for rejecting it. As noted in
Badaracco
v.
Commissioner,
In these circumstances, the incompleteness of the corporate return provides a reason for doubting petitioner’s understanding of the Code. We do not thereby suggest that, for cases in which a corporate return doеs supply all of the information necessary to process a shareholder’s return, the mere fact of completeness is sufficient to establish the corporate return as “the” return of § 6501(a).
Section 6012(a)(2) reads:
“§ 6012. Persons required to make returns of income
“(a) General rule
“Returns with respect to income taxes under subtitle A shall be made by the following:...
“(2) Every corporation subject to taxation under subtitle A ... .”
Since S corporations are now subject to limited taxation, § 6037(a) serves the additional function of determining the assessment period for those taxes. See
Petitioner’s reading of § 6037(a) is sufficiently lacking in textual support to obviate any need to examine legislative history. However, several courts have noted that the history of § 6037 contains evidence in support of the Commissioner’s interpretation. See,
e. g., Green
v.
Commissioner,
“Notwithstanding the fact that an electing small-business corporation is not subject to the tax imposed by chapter 1 of the 1954 Code, such corporation must make a return for each taxable year in accоrdance with new section 6037 .... Such return will be considered as a return filed under section 6012 for purposes of the provisions of chapter 66, relating to limita *531 tions. Thus, for example, the period of limitation on assessment and collection of any corporate tax found to be due upon a subsequent determination that the corporation was not entitlеd to the benefits of subchapter S, will run from the date of filing of the return required under the new section 6037.” S. Rep. No. 1983, 85th Cong., 2d Sess., 226 (1968).
Although the passage would seem to support the Commissioner’s view, petitioner, following the reasoning of the Ninth Circuit in
Kelley
v.
Commissioner,
The Commissioner claims additional support in the Senate Report accompanying the 1982 amendments to Subchapter S, which states in relevant part:
“Under present law, a taxpayer’s individual tax liability is determined in proceedings between the Internal Revenue Service and the individual whose tax liability is in dispute. Thus, any issues involving the income or deductions of a subchapter S corporation are determined separately in ... proceedings involving the individual shareholder whose tax liability is affected. Statutes of limitations apply at the individual level, based on the returns filed by the individual. The filing by the corporation of its return does not affect the statute of limitations appliсable to the shareholders.” S. Rep. No. 97-640, p. 25 (1982).
This passage is of little value to either side. While the views of a Congress engaged in the amendment of existing law as to the intent behind that law are “entitled to significant weight,”
Seatrain Shipbuilding Corp.
v.
Shell Oil Co.,
Petitioner additionally asserts that the returns of shareholders of a Subchapter C corporation cannot be adjusted after the limitations period has run for assessing the corporation’s return, and that therefore S corporation shareholders are entitled to identical treatment. Brief for Petitioner 11-12, 21-22. However, petitioner has not provided a single authority in support of the premise of this assertion. At oral argument, the Commissioner maintained that the opposite is the case, see Tr. of Oral Arg. 27-28, relying mainly on
Commissioner
v.
Munter,
“We have held that the relevant return for determining whether, at the time a deficiency notice was issued, the period for assessment had еxpired under section 6601(a) ‘is that of petitioner against whom respondent has determined a deficiency.’ [Citing Fehlhaber,94 T. C., at 868 .] We have maintained that position consistently, without regard to the nature of the source entity involved. See [cases involving partnerships, trusts, and S corporations].” Lardas v. Commissioner,99 T. C. 490 , 493 (1992).
In any event, it is doubtful that petitioner’s conclusion follows from his premise, for the taxation of C corporations and their stockholders is so markedly different from that of S corporations.
