It has been over a month since my husband left. He feels he can just stop by whenever he wants. When can I change the locks. I live in Pennsylvania

Who owns the house?

Have you filed for a divorce, a restraining order, something to keep him out?

You cannot legally change the locks.

On a personal note - he seems to have the best of both Worlds. He gets to go wherever he wants to go and drop in at the house whenever he wants.

I'd get an Attorney.

... You cannot legally change the locks.
...

I disagree. If he moved out a month ago, he is by no stretch of the imagination a "tenant", so to change the locks could not be an illegal ouster in violation of a landlord-tenant act. Especially if OP has an ownership interest in the house, but even if she doesn't, as an occupant she has the right to change the locks so as to provide herself some measure of security.

I can only tell you in NY - I was getting divorced. He moved out (by verbal agreement). I was told that if I didn't want to hand him abandonment as grounds I had no right to change the locks until I advised him by mail that I intended to do so on a certain date.

I was also told that if I changed the locks and he broke the door down to get in the Police would do nothing because it was also his home - right up until I had him ordered out.

Very well may be different in other States.

If she locks him out I say she will not get anyone to help her if he decides to come back in.

Do we know which State?

I disagree. If he moved out a month ago, he is by no stretch of the imagination a "tenant", so to change the locks could not be an illegal ouster in violation of a landlord-tenant act. Especially if OP has an ownership interest in the house, but even if she doesn't, as an occupant she has the right to change the locks so as to provide herself some measure of security.

I would agree with you if this was a landlord/tenant issue. But its not, it's a divorce issue. We do not know who owns the property or who is the leaseholder. We do not know whether divorce has been filed for or not. Without knowing these things we can't realistically advise whether the OP can change the locks or not.