According to
APA, only Louisiana, New Mexico, Illinois, Iowa, and Idaho currently allow this. This isn't something I'm interested in so I have no idea about the likelihood of adoption in other states.
This board heavily skews towards funded PhDs because the economics are terrible for self-pay PsyD programs. At the high end, you have PsyD programs that will cost $60,000+ a year in tuition and bare bones living expenses. Interest on graduate loans backed by the US govt kick in immediately so over a 20 year period, you could be looking at $350,000+ in principle and interest repayment obligations before you're debt free.
According to the dept of labor, the median psychiatrist salary is $208,000 while the median clinical psychologist salary is only $78,000 (which will be closer to $50,000 gross after federal, state, medicare and other taxes) so it makes a lot more sense to take on huge debt for a MD/DO. Significant grad school loans will majorly impact
all of your post-grad school life decisions.
Fully funded PhD programs in clinical and counseling psychology that provide tuition waivers and small living stipends (as well as the few funded PsyDs out there) are more competitive and require more pre-requisites such as clinical research experience but please explore this option if you think being a psychologist is the right path for you.
If you can be a good candidate for med school, you'd likely be a good candidate for a funded PhD in psychology if you can get active with a psychology research lab and gain those extracurricular experiences while in undergrad or with a post-grad RA year or two. Good luck!