Customers enter a Verizon Wireless store in New York.

The Justice Department has opened an antitrust investigation into potential coordination by AT&T, Verizon and a telecommunications standards organization to hinder consumers from easily switching wireless carriers, according to six people with knowledge of the inquiry.

In February, the Justice Department issued demands to AT&T, Verizon and the G.S.M.A., a mobile industry standards-setting group, for information on potential collusion to thwart a technology known as eSIM, said two of the people, who spoke on the condition of anonymity because the details are confidential.