How do i Reduce the basis of my stock by distributions?

[Hal_Al · Accepted solution]

It depends on the type of distribution. If you receive a tax free distribution (usually, a “return of capital”), you do reduce your cost basis for the amount of the distribution. You show nothing about the distribution, on your tax return. You only adjust the cost basis, on your own records, for when the stock is sold in the future.

Ordinary stock dividends are taxed as income and do not affect your basis.

For distributions of additional shares, your original cost basis remains fixed and is just spread over more shares. For example; if you originally bought 100 shares for $1000, your cost basis was $10/share.  If you receive a distribution of 10 additional shares, your  cost basis in the 110 shares is still $1000, but is now $9.09/share (1000 / 110)

[loch-6]

How would i adjust the cost basis?

[Hal_Al]

It's best explained by example:  if you originally bought 100 shares for $1000, your cost basis was $10/share. You receive a  non dividend distribution in box 3 of form 1099-Div. of $100,  which you do not report on your tax return.
Your cost basis in your 100 shares is now $900 ($9 / share). You make that adjustment, in your own records. It does not go on your tax return, TurboTax will do nothing with the amount in box 3 of the 1099-Div.