The refill limit is schedule-specific. Just like CII get no refills federally, but other schedules allow it. In this case, MA does not limit refills on CVI prescriptions. I agree, the whole thing is weird. But, all of the general controlled substance rules apply (e.g. "A prescription for a controlled substance to be valid shall be issued for a legitimate medical purpose by a practitioner acting in the usual course of his professional practice. The responsibility for the proper prescribing and dispensing of controlled substances shall be upon the prescribing practitioner, but a corresponding responsibility shall rest with the pharmacist who fills the prescription. "). So, every Zantac 300mg Rx in Massachusetts comes with a legally enforceable "corresponding responsibility".