What can I do if I was falsely accused of elder abuse and lost my clients since I work for DHS?

Most likely nothing, as employers have all the marbles & can fire you at will. It’s a losing battle. Unjust termination is hard to prove & it will cost you more money in lawyer fees than it’s worth. Unless you were in a Union, that may help.
Regarding your disqualification with the OIG once you receive a mark against you, it’ll be very difficult if not impossible to get that cleansed from your record.
I am sorry this happened. What were the grounds for dismissal?

If you get nowhere with the DHS call the Dept of Labor. You should have been made aware of an allegations so you could give your side. Then an investigation.

Debrra, terminated or suspended? Are you an employee or a contractor?

If you are an employee of the Department of Human Services, call your line manager. Your employer must advise you about what to do, for example explaining what happens next about the allegations and where you can get help with having yourself represented.

If you are a contractor, you could contact one of the professional associations for people working in the elder care sector and see if they can advise you.

Definitely appeal and follow up if you've been falsely accused. I hope things work out for you.

So sorry for your situation. This is your livelihood. In my opinion, this is wrongful termination of your employment. Is there a system in place where you can file an appeal? Go up the ladder above the person who terminated you? And go above that person's boss's boss? Etc.

If it's too complex, you might need the help of a good attorney to fight for you.

I think it's important that you fight this false allegation or else you will have trouble finding employment.