The first thing you need to do is make sure that you have the authority to act on behalf of your father. If your father executed a Durable Power of
Attorney appointing you to be able to act on his behalf, you will be able to act on his behalf with the IRS. If he has no Durable Power of Attorney and your father's cognitive impairment is not too serious, he may be able to have one prepared for him to sign now. If his cognitive impairment is too much for him to execute a Durable Power of Attorney, you should apply to a court to be appointed his guardian or conservator to be authorized to act on his behalf. The next step is to confirm that the amount that he is alleged to owe is correct. You should consult an accountant both to help ascertain the correct amount owed and to negotiate on your behalf with the IRS for a reduced amount settlement or payments over time.