What to do? Mother passed away, house in my name, but brother, who per her Will inherits 1/2 the house we both live in, owes tax debt (and hasn't done his taxes in about five years)

Hi folks,

So my Mom passed away in 2020. She left 1/2 of her estate to me and 1/2 to my brother. I'm the executor of her estate. The estate is only the house and what's in it. The house is in my name and I'm working on assuming the mortgage. So my brother hasn't done his taxes in about 5 or 6 years. He hasn't done anything to get his taxes done, but he recently said he'd be willing to give me financial POA so that I can start working on that. My fear is that the IRS will be able to put a lien on the house or even seize it. He's on Social Security, and I'm also afraid they'll garnish that and the small retirement income he has from the job he had before he got laid off in 2016. We can't afford a tax lawyer. My mom used to have a retired AARP person do hers and I'm thinking of trying to go that route. Do you have any knowledge of this kind of situation, or places I can go for help?

Thank you for any and all advice!