Title more or less says it all - I'd like to buy new rims, do I need new TPMS? Or can I use my old ones?

Thanks!

You can transfer the TPMS from the old to the new rims. You may need to buy a "stem" kit with new gaskets - they're inexpensive (> $10) - available at most dealers and will help ensure removal and reinstall doesn't cause leaks. Also, be certain the tire installer knows there are TPMS on the rims so they don't damage them.