T-Mobile USA has joined the Rural Cellular Association (RCA), which bills itself as standing up for "competitive wireless providers" and is in frequent conflict with Verizon Wireless and AT&T.
The RCA and T-Mobile apparently set aside their differences over AT&T's failed mega-merger, a deal the RCA was vehemently against.
T-Mobile did not respond to questions about its membership but said in a statement that it shared "RCA’s goal of promoting a healthy, competitive wireless industry."
T-Mobile is also a member of CTIA, whose roster includes AT&T and Verizon Wireless.
CTIA has steered clear of taking stances on issues that pit its larger members against its smaller members, such as mandatory data roaming, and kept out of the debate on the proposed merger between AT&T and T-Mobile.
The buyout's failure has put T-Mobile back in competition against AT&T and Verizon. The RCA frequently lobbies on behalf of policies opposed by the country's two largest operators.
Steven Berry, president and CEO of the RCA, said T-Mobile's presence would add to the association's influence with lawmakers.
"With all the challenges facing the mobile industry, it is more critical than ever for competitive carriers to come together in the advocacy fight, and a stronger membership will certainly help ensure our voices are heard at the FCC, on Capitol Hill and at the White House," he said.
T-Mobile is not the only national operator to join the RCA. Sprint joined the group last spring, citing "issues of mutual concern" with RCA members.
At the time, both Sprint and the RCA were fighting AT&T's buyout of T-Mobile. Sprint is also a member of CTIA.
RCA rules forbid operators with more than 10 million subscribers from qualifying as full voting members, but companies like Sprint and T-Mobile that exceed the subscriber limit can join as an affiliate member.
The trade group currently has more than 250 members from the operator and vendor communities.