Proper billing for CPT® code 82270

I need some clarification on how/when to bill 82270. I've had some recent denials from Medicare. Please tell me if this assessment is correct:

Bill 82270 when patient returns cards that have been taken home to collect specimen. (should only be billed with an office visit if pt brings cards back in when he/she is seeing doctor - not to be billed at the time the cards are given to patient to take home)

For 82270, must use screening codes of V76.41 or V76.51

Only on patients 50 and older

Any rectal exam performed in office would be covered in the E/M code.

Please tell me if I'm correct. If not, please explain how to correctly use this code. I want to know for sure before I provide the information to my doctors.
Thanks,

Surprised I haven't received a response as of today, so thought I would resubmit. Would really like to know if my assessment is correct.
Thanks,