This form will also provide cost basis information for applicable accounts, on the sale or exchange of fund shares during the previous calendar year. (franklintempleton.com)
Most mutual fund companies will provide cost basis information for you when you sell your shares — averaged according to the Single Category method. (fool.com)
Prior to 2012, mutual fund and brokerage companies were not required to keep track of cost basis information for investors. (mutualfunds.com)