She was concerned NorthTec "doesn't value wisdom and institutional knowledge of older staff. That the message is that grey hair isn't wanted."
NorthTec said the opportunity for retirement or resignation was entirely voluntary and all positions vacated would be backfilled.
"The benchmark age of 62 was considered an appropriate level to recognise the value of learned experience.
"The option of voluntary retirement/resignation gives NorthTec an opportunity to better reflect the demographics of our current student base and the regional profile," NorthTec said in a statement.
NorthTec said the $20,000 allowance was mid-point of the average redundancy payout across the organisation.
But the NorthTec employee said the job prospects for someone past 62 in Northland were "zero" and said while she had chosen to stay, she was concerned there would be more restructuring in the future.
"We think there are more reviews coming and I now feel really vulnerable that I will be picked to go because they have said they want younger people and more Maori staff to better match their students," she said.
But NorthTec said no new organisation-wide restructure was planned.
"However, ongoing incremental changes will continue to be made to ensure the viability of the organisation going forward, and prevent where possible, the necessity for such drastic structural changes in the future. "
Decisions for the NorthTec review have been documented and communicated several times during the period of consultation and decision-making, the polytech said.
Chan Dixon, organiser of the Tertiary Education Union branch at NorthTec, said many staff - including those under the age of 62, shared the same concerns as the unnamed staff member.
"Enticing an unspecified number of older people into leaving their jobs is a flawed way to manage any organisation, not to mention ageist."
Meanwhile, staff who were directly affected by the restructuring were given the chance to choose voluntary redundancy.
The report said where a surplus staffing situation arose within a team, one or more individuals may prefer to depart voluntarily with their colleagues retaining remaining positions.