with whom The Chief Justice joins, concurring in the judgment.
The question in this case is whether the illegitimate children of a federal employee, who lived with his children after their birth and had a legal obligation to contribute to their support until his death, are eligible to receive survivors’ benefits under the Civil Service Retirement Act, 5 U. S. C. § 8331 et seq. The statutory definition of “child” under that Act includes a “recognized natural child who lived with the employee ... in a regular parent-child relationship.” 5 U. S. C. § 8341 (a) (3) *35(A) (ii). Because I agree that these children satisfy the statutory definition, I concur in the judgment of the Court. I write separately because I do not believe that the Court’s broad construction of the “lived with” requirement is compatible with congressional intent or necessary to avoid constitutional difficulties.
The Court recognizes that the “lived with” requirement could serve governmental purposes by providing proof of either paternity or dependence. The Court concludes that the “lived with” requirement is not designed to prove paternity because the statute separately requires that an eligible illegitimate be a “recognized natural child.” Ante, at 30. I agree.
I cannot accept so easily the Court’s further-conclusion that the “lived with” requirement was not designed to prove dependency. Although the 1966 amendment demonstrates that the “lived with” requirement cannot be interpreted to demand that more than one-half of a child’s support come from the deceased parent, it does not demonstrate that Congress intended to eliminate entirely the dependency requirement. As a matter of statutory construction and common sense, the statement that an illegitimate who fulfills the “lived with” requirement need not meet an additional dependency requirement, ante, at 32, quoting H. R. Doc. No. 402, 89th Cong., 2d Sess., 41 (1966), indicates that Congress intended the “lived with” test to serve as the functional equivalent of a dependency requirement. The Court’s assumption to the contrary deprives the “lived with” requirement of any legislative purpose. Rather than construe a statutory provision to serve no identifiable congressional goal, I would conclude that Congress intended the “lived with” requirement to serve as a means through which illegitimate children may prove actual dependency on the deceased parent.
Congress may require illegitimate children to demonstrate actual dependency even though legitimate children are presumed to be dependent, Mathews v. Lucas, 427 U. S. 495, 507-509 (1976), so long as the means by which illegitimates *36must demonstrate such dependency are substantially related to achievement of the statutory goal. Lalli v. Lalli, 439 U. S. 259, 275-276 (1978) (opinion of Powell, J.); see Trimble v. Gordon, 430 U. S. 762, 770-773 (1977). The possible constitutional infirmity in the Government’s construction of the statute is its assumption that only illegitimates who “lived with” a parent at the time of his death were actually dependent. Such a requirement may be unconstitutionally restrictive because, as in this case, it would bar the claims of children who lived with their father for some part of their lives, and who received support from their father until his death.*
The recognition of the children’s claim in this case clearly does not frustrate the congressional intent that only dependent illegitimate children receive survivors’ annuities. I therefore would hold that children who show a continuing relationship of dependency with their father, which includes living with him in the past and receiving support from him when they lived apart, satisfy the requirement of 5 U. S. C. § 8341 (a)(3)(A)(ii). I do not believe, however, that the Court needs to find the requirement satisfied no matter when the child lived with the deceased parent. In some circumstances proof of a domestic living situation at some far distant period in the child’s life may not demonstrate actual dependency. Accordingly, I would go no further than concluding that these children have satisfied the “lived with” requirement.
1 believe that the Court errs in assuming that its broad interpretation of the “lived with” requirement will always avoid constitutional difficulty. The imposition of the “lived with” requirement as a test of actual dependency may be unconstitutional in a case in which a father had always supported, but never lived with, an illegitimate child.