Modifier PT, and 33

I was under the impression that PT modifier was used only for Medicare screening colonoscopies turned diagnostic. I just read somewhere that Anthem also uses this modifier. Does anyone know if all commercial insurance use this modifier?

Also Modifier 33 is used for commercial to show preventative services correct?
Can you use this on the pre precedure visit as well?

re: Modifier PT, and 33

http://www.anthem.com/provider/noapplication/f1/s0/t0/pw_b157159.pdf?refer=ahpprovider&state=oh
As far as others go, it will be individual policy.
http://community.cengage.com/Site/infohealthconnect/b/health_insurance/archive/2011/05/03/new-cpt-modifier-33-preventive-services-effective-january-2011.aspx