I owe the IRS a great sum of monies from a 401K distribution many years ago and have not been able to pay to pay those funds back to them. My CPA calculated the withholding incorrectly thus, left me owing that owed withholding. I am the executor of my Mom's Estate and want to know how this factor will affect the distribution of her assets to my brothers upon her death. I want to do whatever I can (short of paying the IRS off prior to her death - which will not happen since it is a very large sum of monies)to not affect my brothers inheritance. Need advise.

The fact that you owe money to the IRS has absolutely nothing to do with how your mother's estate is handled. As executor you have a fiduciary duty to manage and protect your mother's estate, and distribute the assets to the heirs in accordance with her wishes and state law. The fact that you personally owe money to a creditor does not affect what happens to your mother's estate in the least - the estate's assets can't be garnished or attached by your creditors - at least as long as they remain in your mother's estate. Now, once you distribute the estate assets to the heirs (including yourself I presume) then what you personally inherit becomes your property and so may be used to help settle your IRS debt. The portion our brothers inherit becomes theirs, and are not impacted in any way by your personal debts.

The assets in question belonged to your mother. If the assets are to be divided equally, once probated, your brothers portion should not be an issue for your taxes. As executor, your job is to do what the will says. Your portion MAY be a different story. IRS can go after some assets. You may also have a state issue depending on where you live and what the asset value is. I would personally try to work something out with your proceeds and get them off your back or it will follow you forever.

Once divided, they can take what you get from the estate, they can not take the shares of anyone else.