I don't claim to understand the codes. The medical associations establish codes to help medical professionals 'communicate' what treatment is being performed to the insurance companies. There were old codes that represented a 50-60 minute session and apparently that was changed to new codes for different lengths of sessions.

Here's a link that helped me understand a little better.

My therapist had a typical 55 'talking' time and 5 minutes of administrative. New codes list 30 minute, 45 minute, and 60 minute code choices that replace the 50-60 code. My therapist had always done a 55 minute session and I assume billed it under the 60 minute code. She dropped my insurance a few months ago and changed her rates with me, so I stopped going to her for that and because I wanted a change anyway. it sounds like your T is using the "45 minute" code. It seems she shouldn't be charging the same amount for less time.