(CNN) -- Licenses were awarded to 20 medical marijuana dispensaries in Massachusetts, the first in the state after a voter-approved law went into effect in 2013, state officials announced Friday.
The Massachusetts Department of Health and Human Services said 100 finalists applied for licenses and were judged on how they served the public health, their security and strength of their business plans, as well as their focus on the ability to meet patients' needs.
"Health officials designed a rigorous process for vetting applicants," said the statement, citing a process that included a selection committee that determined the ability of each applicant to "meet overall health needs to registered patients while ensuring public safety."
The law went into effect January 1, 2013, and allows the department to register up to 35 nonprofit registered marijuana dispensaries.
In addition to the 20 approved, eight other applicants were qualified but the proposed locations were rejected, the statement said. Those applicants will be able to reapply in other counties that do not have a licensed dispensary, according to the department.
Patients who have a written certification from a physician for medical marijuana will be registered in an online system, according to the department.
Medical marijuana dispensaries serve clients who suffer ills ranging from cancer to AIDS to chronic pain.
Proponents say the drug's pain-relieving properties offer an alternative for cancer patients undergoing chemotherapy or radiation treatments.
Eighteen states have either decriminalized or allowed medical marijuana in some fashion. While the state laws have allowed dispensaries to open, they remain illegal under federal law. Fourteen states allow dispensaries, according to the National Conference of State Legislatures.