Smiler said the intention to adjust the policy by bringing in caps was one area of concern and lack of consultation so far was another.
However, dean of the Otago Medical School Professor Rathan Subramaniam said discussions were at an early stage and there was not yet a formal proposal for change.
A discussion document was presented to the university's medical admissions committee last week.
"If, at the end of initial discussions, any change to formal regulations is to be considered, that will be subject to the normal university procedures, including opportunities for consultation," Subramaniam said.
The university was extremely proud of its Mirror on Society policy, he said.
"This policy has led to record numbers of Māori and Pasifika students entering the professional programmes in the health sciences division. In light of that success ... the university is currently considering the desirability of updating the regulations to better reflect the policy ... and to enhance transparency."
Otago University Medical Students' Association president Anu Kaw said students did not know what was driving proposed changes.
"We're not sure why there's this urgency to fix a policy that is not broken."
Smiler, a third-year medical student at Otago, said he wanted to make sure proper processes were undertaken.
"A decision that will impact on Māori health outcomes for decades surely warrants consultation with appropriate Māori voices."
Kaw expressed the same concern about Pacific voices.
The 11 student associations issued a collective statement that raised similar themes.
"We hold considerable concerns about what is being proposed and what this means for students."
The associations argued any caps should reflect the aim of "creating a health workforce that reflects the population it serves".
Subramaniam said the university would continue to strive to deliver a health workforce representative of the make-up of the population.
Students applying for the medicine programme in 2021 would not be affected by any changes to the policy.