The union representing primary school teachers says hundreds of teachers may have missed out on a special $10,000 allowance because no one knew about it.
Ministry of Education figures show that 121 graduate teachers across the country received the Voluntary Bonding Scheme last year.
The government has announced it will extend its Voluntary Bonding Scheme to all primary schools in Auckland, not just low-decile schools nationally.
The national scheme was introduced in 2009 to attract and retain new teachers in low-decile schools which had trouble recruiting.
Eligible teachers get the $10,000 dollars at the end of their third year teaching, and a further $3500 at the end of their fourth or fifth years.
Fifty-nine teachers have been granted the Voluntary Bond Scheme this year, that figure has been dropping since 2013 when 283 teachers were given grants. Both secondary and primary school graduate teachers are eligible.
Largely, the extended scheme has been welcomed by the primary teachers' union, the New Zealand Educational Institute.
But president Lynda Stuart said the government had kept the original scheme under wraps until this week, when it said it would extend it to all schools.
Almost no principal or teacher knew the scheme existed and many have missed out as a result, Ms Stuart said.
In the past two days more than 300 out of 2000 teachers who have contacted the union were eligible under the original scheme, she said.
"When you know that there is a staffing crisis and you're looking at ways you can alleviate that, then surely if you do have a scheme like that, you would be looking to publicise it."
Ms Stuart has called for the government to give the money to those who were eligible, but missed out.
The institute said the government must provide an added incentive for low-decile schools to ensure they can still attract teachers.
It also said that the scheme should apply to cities and regions beyond Auckland such as Queenstown and Blenheim, which were also struggling to retain teachers.