A combination file photo shows Wells Fargo, Citigbank, Morgan Stanley, JPMorgan Chase, Bank of America, JPMorgan, and Goldman Sachs from Reuters archive.
The investigation is targeting JPMorgan Chase & Co , Goldman Sachs Group Inc , Bank of America Corp , Citigroup Inc , Wells Fargo & Co (WFC.N) and Morgan Stanley (MS.N).
"American banks should never put political agendas ahead of the secure retirement of their clients," Arizona AG Mark Brnovich said in a statement.
"The last thing Americans need right now are corporate activists helping the left bankrupt our fossil fuel industry," Texas AG Ken Paxton said, adding that the banks practices potentially violate consumer protection laws.
JPMorgan declined to comment, while the other five banks did not immediately respond to requests for comment.