29 CFR § 4050.304 - Diligent search.
(a) Search requirement. For each distributee of a subpart C plan who is described in § 4050.303(b), the plan administrator must, within the time frame described in paragraph (d) of this section, have diligently searched for each distributee of the plan whose location the plan administrator does not know with reasonable certainty upon close out, using one of the following two methods:
(b) Commercial locator service method -
(2) Meaning of “commercial locator service.” For purposes of this section, a commercial locator service is a business that holds itself out as a finder of lost persons for compensation using information from a database maintained by a consumer reporting agency (as defined in 15 U.S.C. 1681a(f)).
(c) Records search method -
(v) Using an internet search method for which no fee is charged, such as a search engine, a network database, a public record database (such as those for licenses, mortgages, and real estate taxes) or a “social media” website.
(2) Limits on method. For purposes of this section -
(i) Searching is not feasible to the extent that, as a practical matter, it is thwarted by legal or practical lack of access to records, and
(ii) Searching is not affordable to the extent that the cost of searching (including the value of labor) is more than a reasonable fraction of the benefit of the distributee being searched for. In no event would searching need to be pursued beyond the point where the cost equals the value of the benefit.
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