Is there a law or requirement that the landlord paint before each new tenant?

Hello bren:

No, not at all.

excon

There were at one time a few cities that had that requirement, but there is no Federal law about it, I may paint the inside of my rentals every 5 to 8 years if I have to. But often my renters will just paint them to make it nicer for theirself

It's not likely that there is such a law but if there is, it would be a municipal law or regulation. Check with your town's building department to be sure.