Are wealth advisors/financial planners considered professional service providers (PSP) or non-bank financial institutions (NBFI))? Or can the be both? Does anyone have a reference as to what an NBFI is vs a PSP? Thank you.

You can find financial institutions in Appendix D of the BSA Exam Manual.
The list includes:

A broker or dealer in securities or commodities.
An investment banker or investment company.

The Professional Service Provider section of the exam manual provides a description and examples:

A professional service provider acts as an intermediary between its client and the bank. Professional service providers include lawyers, accountants, investment brokers, and other third parties that act as financial liaisons for their clients. These providers may conduct financial dealings for their clients. For example, an attorney may perform services for a client, or arrange for services to be performed on the client’s behalf, such as settlement of real estate transactions, asset transfers, management of client monies, investment services, and trust arrangements.

Thanks BrianC

Ok so if the customer specializes in tax prep, book keeping, and payroll that would probably put them in a PSP category. If it were a Charles Schwab type company, then that is a NBFI? Correct?