I read that if you make a wash sale in a taxable brokerage account and buy the same stock in a tax-advantaged IRA, the wash rule says that the loss in the taxable brokerage account is now permanently disallowed. The stated reason being is that the disallowed loss can’t be added to the cost basis of your position in your IRA.
However, let’s say you didn’t completely liquidate your position in the taxable brokerage. Can the disallowed loss be added to the cost basis of that position and deferred until later?