Sorry to be so late to this party, I work in Pediatrics, land of vaccines, I can clear up a few things:
As far as that out of state Blue plan that wouldn't cover 90620 with routine Z23- Been there, done that. It was a very interesting conversation with that plan, The representative went through the following codes with us : Q89.01, Z90.81, D68.4, D68.2, Z20.811, all not routine, and also not covered. The ONLY code that plan would cover for 90620, was "D84.1, Defects in complement systems" which is a rare diagnosis, but possible. I hope this info helps others.
90620 is to be given from age 16 and up, given in two doses for Bexsero (* there is also a 3 dose regimen product available out there-90621).
90734 is NOT the same thing, in ANY way to 90620. They are TWO different products, used in two different age groups, comprised of different "serogroups".
90620 Meningococcal Serogroup B vaccine by Bexsero AND 90734 Meningococcal Conjugate vaccine, serogroups A.C.Y. and W-135 (tetravalent) (Menactra/Menveo)
CDC recommends vaccination with a meningococcal conjugate vaccine 90734 for all preteens and teens at 11 to 12 years old, with a booster dose at 16 years old. Young adults (16 through 23 year olds) also may be vaccinated with a serogroup B meningococcal vaccine 90620
Good luck!