In preparing my previous year tax return, I used data from Vanguard's "Average Cost Summary" to obtain the "Average Cost Basis". Would this figure already reflect the reinvested dividends added to the cost basis or do I need to add the dividends paid out on previous years to this figure to get an adjusted cost basis?
========================================= MODERATOR'S COMMENT: Chances are very very good Vanguard already included the reinvested dividends in their average cost basis calculation.