If the brokerage company was distributing your mother's account to her TOD beneficiaries, it should not have been reported on Form 1099-C, Cancellation of Debt.
Please provide clarification on the actual tax reporting document received from the brokerage company if it was NOT a 1099-C, Cancellation of Debt, where debts owed to someone were cancelled instead of paid by the estate upon death.
Transfer on Death is an appropriate way to name the account so that it passes upon death to beneficiaries to avoid probate.
