delivered the opinion of the Court.
Petitioners, St. Martin Evangelical Lutheran Church (St. Martin), at Watertown, S. D., and Northwestern Lutheran Academy (Academy), at Mobridge in that State, claim exemption with respect to their school employees from taxes imposed by the Federal Unemployment Tax Act (FUTA), 26 U. S. C. §§ 3301-3311 (1976 ed. and Supp. Ill), and by South Dakota’s statutes complementary thereto, S. D. Codified Laws § 61-1-1 et seq. (1978 and Supp. 1980). The exemption is claimed on both statutory and First Amendment grounds. The provisions primarily at issue are FUTA’s § 3309 (b)1 and South Dakota’s § 61-1-10.4.2
*775I
A
FUTA appeared originally as Title IX of the Social Security Act of 1935, 49 Stat. 639, and was enacted in response to the widespread unemployment that accompanied the Great Depression. It called for a cooperative federal-state program of benefits to unemployed workers.3 The Act has undergone a series of amendments that progressively have expanded coverage of the Nation’s work force.4
This case concerns one of the more recent of those amendments, namely, that effected by § 115 (b)(1) of the Unemployment Compensation Amendments of 1976, Pub. L. 94-566, 90 Stat. 2670. The Secretary of Labor has determined that this statute rendered nonprofit church-related primary and secondary schools subject to FUTA. The South Dakota authorities went along with that ruling in their interpretation of the State’s amended statute. Petitioners are among those religiously affiliated schools so claimed to be required to pay the FUTA and South Dakota taxes. They contest this construction of the statutes. They argue also, however, that holding them subject to the taxes would violate both *776the Free Exercise Clause and the Establishment Clause of the First Amendment.
B
Proper understanding of the effect of the 1976 amendment requires a review of FUTA’s development. From 1960 to 1970, FUTA, by §3306 (c)(8), unrestrictedly excluded from the definition of “employment” all “service performed in the employ of a religious, charitable, educational, or other organization described in section 501 (c)(3) which is exempt from income tax under section 501 (a).” Pub. L. 86-778, § 533, 74 Stat. 984.5 Under this definition, nonprofit church-related schools, of course, were exempt from the tax. A 1970 amendment, however, served to narrow that broad exemption of nonprofit organizations.6 See Employment Security Amendments of 1970, Pub. L. 91-373, § 104 (b)(1), 84 Stat. 697. The amendment generally required state coverage of employees of nonprofit organizations, state hospitals, and institutions of higher education. Simultaneously, however, *777Congress enacted a new and narrower exemption of nonprofit organizations and governmental entities. So far as pertinent to this case, that exemption was set forth in a new § 3309 (b), which then provided:
“This section shall not apply to service performed—
“(1) in the employ of (A) a church or convention or association of churches, or (B) an organization which is operated primarily for religious purposes and which is operated, supervised, controlled, or principally supported by a church or convention or association of churches;
“(2) by a duly ordained, commissioned, or licensed minister of a church in the exercise of his ministry or by a member of a religious order in the exercise of duties required by such order;
“(3) in the employ of a school which is not an institution of higher education . . .
No one, including the Secretary of Labor, disputes that church-run elementary and secondary schools remained exempt under this new § 3309 (b).
In 1976, Congress again amended the Act. Unemployment Compensation Amendments of 1976, Pub. L. 94-566, § 115 (b)(1), 90 Stat. 2670. The effect of the 1976 amendment, so far as pertinent to this case, was to eliminate completely the theretofore existing subsection (b)(3).7 Subsections (b) (1) and (b)(2), dealing specifically with religious employment, remained unchanged.8
*778In 1978, the Secretary of Labor announced, in a letter made public, that the 1976 repeal of § 3309 (b) (3) of FUTA was
“clearly intended to result in State coverage of church-related schools, whose employees constitute over 80 percent of the employees of all nonprofit schools. In light of the repeal of 3309 (b)(3), we think the only services performed in the schools that may reasonably be considered within the scope of the exclusion permitted by 3309 (b)(1) are those strictly church duties performed by church employees pursuant to their religious responsibilities within the schools.” Letter dated April 18, 1978, of Secretary Marshall to the Most Reverend Thomas C. Kelley, O. P., General Secretary, United States Catholic Conference.
The Secretary also ruled that neither § 3309 (b)(1)(A) nor § 3309 (b)(1)(B) was applicable to church-run schools. He notified the States, and they took steps for the collection of unemployment taxes from church-related schools. See Employment and Training Administration, U. S. Department of Labor, Unemployment Insurance Program Letter No. 39-78 (May 30, 1978), reprinted in [1978 Transfer Binder] CCH Unemp. Ins. Rep. ¶ 21,522.
II
Both St. Martin and the Academy are members of the Wisconsin Evangelical Lutheran Synod and, as such, are organizations exempt from federal income tax under 26 U. S. C. §501 (c)(3). St. Martin operates a state-certified elementary Christian day school at Watertown that offers kindergarten through eighth-grade education. The school, which is not a separate legal entity from the church, is controlled by a Board of Education elected from the local congregation. The congregation entirely finances the school’s operation. The Academy is a state-certified 4-year secondary school at Mobridge and is owned, supported, and controlled by the *779Synod. It, also, is not separately incorporated. Approximately half of its students go on to become ministers within the Church. According to the record, all courses given at St. Martin and at the Academy are taught from a religious point of view based on the Synod’s scriptural convictions.
When South Dakota proposed to tax them under § 61 — 1— 10.3, petitioners took an administrative appeal. The Appeals Referee of the State’s Department of Labor — Unemployment Insurance Division ruled that service performed by employees of each petitioner was “employment” within the meaning of the statute. Although finding that the Synod “believes a theological basis exists for their schools” and operates them because it “holds the conviction that training of the youth involves both education and religion and that the two are so closely interwoven they cannot be separated,” App. to Pet. for Cert. A-36, the Referee declined to rule that petitioners were exempt under § 61-1-10.4, the state analogue to 26 U. S. C. § 3309 (b). See nn. 1 and 2, supra. He ruled that petitioners were not eligible for exemption under § 61-1-10.4 (1) (a) because, in his view, the term “church,” as used in that section, referred only to the “individual 'house of worship’ maintained by a particular congregation.” App. to Pet. for Cert. A-43. He also ruled, ibid., that they were ineligible for exemption under § 61-1-10.4 (1) (b) because “the primary purpose of the schools is education.”
On appeal, the Hughes County Circuit Court reversed, finding the Referee’s decision clearly erroneous. App. to Pet. for Cert. A-25. The court ruled that both St. Martin and the Academy were exempt under § 61-1-10.4 (1) (b); that the term “church” referred to “an organization of worship-pers,” rather than to a “house of worship”; and that the primary purpose of the schools was the propagation of the Synod’s faith, a religious concern. App. to Pet. for Cert. A-30 to A-33. The South Dakota Supreme Court, by a divided vote, in turn reversed the judgment of the Circuit Court, and held petitioners subject to the unemployment *780compensation taxes.9 In re Northwestern Lutheran Academy, 290 N. W. 2d 845 (1980). Noting the growing number of conflicting federal and state decisions on this issue,10 we granted certiorari. 449 U. S. 950 (1980).
Ill
A statute, of course, is to be construed, if such a construction is fairly possible, to avoid raising doubts of its constitutionality. Crowell v. Benson, 285 U. S. 22, 62 (1932); Machinists v. Street, 367 U. S. 740, 749-750 (1961); United States v. Clark, 445 U. S. 23, 27 (1980). Accordingly, we turn first to the federal statute itself. From our reading of the legislation and of its history, we conclude that the only reasonable construction of 26 U. S. C. §3309 (b)(1) is one *781that exempts petitioners’ church-run schools, and others similarly operated, from mandatory state coverage.
A
Section 3309 was added to TUTA in 1970. Although the legislative history directly discussing the intended coverage of its subsection (b)(1) is limited,11 the House Report had the following explanation:
“This paragraph excludes services of persons where the employer is a church or convention or association of churches, but does not exclude certain services performed for an organization which may be religious in orientation unless it is operated primarily for religious purposes and is operated, supervised, controlled, or principally supported by a church (or convention or association of churches). Thus, the services of the janitor of a church would be excluded, but services of a janitor for a separately incorporated college, although it may be church related, would be covered. A college devoted primarily to preparing students for the ministry would be exempt, as would a novitiate or a house of study training candidates to become members of religious orders. On the other hand, a church related (separately incorporated) charitable organization (such as, for example, an orphanage or a home for the aged) would not be considered under this paragraph to be operated primarily for religious purposes.” H. R. Rep. No. 91-612, p. 44 (1969).
*782The Senate Report contained identical language. See S. Rep. No. 91-752, pp. 48-49 (1970).
Respondent would read this discussion, as the South Dakota Supreme Court majority did, to mean that Congress in 1970 intended to bring within mandatory state coverage all institutions of higher education, including those with no separate legal existence from the church or churches that operate them, except for the narrow category of seminaries and novitiates. From this, respondent extrapolates that Congress intended §3309 (b)(1) to be read very narrowly, and that the later 94th Congress, in 1976, similarly intended to include within mandatory state coverage all primary and secondary educational institutions, including those entirely within the internal structure of churches.
The above quotation from the 1969 House Report, and its Senate counterpart, however, are susceptible of a simpler and more reasonable explanation that corresponds directly with the language of the subsection. Congress drew a distinction between employees “of a church or convention or association of churches,” §3309 (b)(1)(A), on the one hand, and employees of “separately incorporated” organizations, on the other. See H. R. Rep. No. 91-612, at 44. The former uniformly would be excluded from coverage by §3309 (b)(1) (A), while the latter would be eligible for exclusion under § 3309 (b) (1) (B) only when the organization is “operated, supervised, controlled, or principally supported by a church or convention or association of churches.” 12 To hold, as re*783spondent would have us do, that “organization” in subsection (b)(1)(B) also includes a church school that is not separately incorporated would make (b)(1)(A) and (b)(1)(B) redundant.
The distinction between church schools integrated into a church’s structure, and those separately incorporated, is given further credence by the statute’s use of specific words. The Department of Labor would interpret the term “church” in § 3309 (b)(1) as limited to the actual house of worship used by a congregation. See Brief for United States as Amicus Curiae 14-15.13 This reading, however, appears to us to deny several of FUTA’s phrases their intended meaning. Section 3309 (b), exempting “service performed — (1) in the employ of (A) a church . . . ,” is phrased entirely in terms of the nature of the employer, and not in terms of the work performed or the place at which the employee works. Congress further defined “employer” in § 3306 (a) as “any person who — . . . paid wages . . . or . . . employed at least one individual” (emphasis added). It defined “employee” as “any individual who, under the usual common law rules applicable in *784determining the employer-employee relationship, has the status of an employee.” §§ 3306 (i) and 3121(d)(2). Thus, to hold “church” synonymous solely with a physical building that is a house of worship contradicts the phrasing of the statute.14 The word “church” in § 3309 (b) must be construed, instead, to refer to the congregation or the hierarchy itself, that is, the church authorities who conduct the business of hiring, discharging, and directing church employees.15
We conclude that, at the time of its enactment in 1970, §3309 (b)(1)(A) was meant to apply to schools, like petitioners’, that have no separate legal existence from a church, or, as in the Academy’s case, from a “convention or association of churches.” As the Referee found, St. Martin directly finances, supervises, and controls its school’s operations. The Synod similarly supports and controls the Academy. Only teachers trained and certified by the Synod may teach at either school, and, again as the Referee found, these teachers, both male and female, “receive a divine, life-long call” to the church. App. to Pet. for Cert. A-38. Male teachers (“teaching ministers”) have equal status in the church and an equal vote on Synod matters, including matters of doctrine, with preaching ministers. Id., at A-37. Neither school has a separate legal existence. Thus, the employees *785working within these schools plainly are “in the employ . . . of a church or convention or association of churches . . . 16 §3309 (b)(1)(A).
B
The 1976 Amendments did not alter the scope of § 3309 (b) (1), either directly or by implication.17 Congress, in eliminating the old § 3309 (b)(3), made no change in § 3309 (b) (1). It did not discuss churches or church schools, and it intimated that §3309 (b)(1) remained unchanged. See, e. g., H. R. Rep. No. 94-755, pp. 23, 41, 55-56 (1975) (explaining the then-current coverage of § 3309 (b) and the anticipated effect of the repeal, and containing no indication that the proposed amendments would alter §3309 (b)(1)).
*786Respondent places particular emphasis on legislative statements expressing an intention, for example, to extend coverage “on the basis of services performed for all educational institutions,” H. R. Rep. No. 94-755, at 56,18 and to “employees of non-profit elementary and secondary schools,” id., at 2. See also id., at 41 (“This section requires States, as a condition for tax offset credit to their employers, to extend coverage to employees of non-profit primary and secondary institutions of education, thus broadening present required coverage limited to non-profit institutions of higher education”); S. Rep. No. 94H265, pp. 2, 9-10 (1976).
These references are simply too general and too ambiguous to bear the weight respondent would assign to them.19 There is no indication that Congress, in these references, had in mind the scope of § 3309 (b)(1) and religious organizations. Rather, all the evidence demonstrates that it was concerned solely with the then-existing § 3309 (b)(3) and secular educational institutions, particularly the public schools. Furthermore, the reported comments implying total coverage of all educational institutions, as a result of the repeal of the former §3309 (b)(3), could not be taken as literally true because the 1970 Report expressly had noted that a college *787“devoted primarily to preparing students for the ministry,” H. R. Rep. No. 91-612, at 44, would be exempt. All institutions of higher education had not been covered by the 1970 Amendments.
Respondent also relies on a single statistic estimating the number of employees newly to be covered as a result of the repeal of the then § 3309 (b)(3). See S. Rep. No. 94H265, at 8 (table). This statistical reference, to the effect that 242,000 employees of nonprofit organizations would be covered by the 1976 repeal of subsection (b)(3), is much too meager to sustain respondent’s position. The Committee Report’s table containing this figure is devoid of any explanation, source, or supporting data. The South Dakota Supreme Court relied on the figure, however, reasoning that because it “approximates the total number of teachers in all nonprofit elementary and secondary schools” in 1975,20 290 N. W. 2d, at 849, and n. 5, Congress must have included within that number religious-school teachers, who constitute more than half the staff of all private elementary and secondary schools in the United States. Yet, in repealing § 3309 (b)(3), Congress intended to include not just full-time teachers, but all employees of the newly covered nonprofit private elementary and secondary schools (custodians, cafeteria workers, nurses, part-time help, counselors, etc.). Thus, the inclusion of all employees in nonprofit private lower schools within the number of persons brought within FUTA by the repeal would far exceed the 242,000 contained in the Report’s table, rendering it, in our view, of dubious significance for the present issue.
This legislative history does not reveal any clear intent to repeal § 3309 (b)(1) or to alter its meaning. The Court has *788had frequent occasion to note that such indefinite congressional expressions cannot negate plain statutory language and cannot work a repeal or amendment by implication. “In the absence of some affirmative showing of an intention to repeal, the only permissible justification for a repeal by implication is when the earlier and later statutes are irreconcilable.” Morton v. Mancari, 417 U. S. 535, 550 (1974); see also Watt v. Alaska, ante, p. 259; TV A v. Hill, 437 U. S. 153, 189-190 (1978); FTC v. A. P. W. Paper Co., 328 U. S. 193, 202-203 (1946); Posadas v. National City Bank, 296 U. S. 497, 503-505 (1936); United States v. Noce, 268 U. S. 613, 618-619 (1925); United States v. Greathouse, 166 U. S. 601, 605 (1897). This long-established canon of construction carries special weight when an implied repeal or amendment might raise constitutional questions. See NLRB v. Catholic Bishop of Chicago, 440 U. S. 490 (1979). We therefore hold that the repeal of § 3309 (b) (3) did not alter the meaning of § 3309 (b)(1). Petitioners are eligible for exemption under subsection (b)(1)(A) by virtue of the nature of their relationship to the church bodies that employ them.
This makes it unnecessary for us to consider the Pirst Amendment issues raised by petitioners.
The judgment of the Supreme Court of South Dakota is reversed, and the case is remanded to that court for further proceedings not inconsistent with this opinion.
It is so ordered.