The number of people accessing the subsidy in Otago has dropped by about 20% in the past four and a-half years.
Figures from the Otago District Health Board show at its peak almost 500 people were funded for carer support in 2004, which dropped to less than 200 at its lowest in 2007.
Carers' Society Otago community worker Susan Easterbrook said information was not freely available that the subsidy existed.
"Every day I come across people who haven't heard of it, but would be entitled to it."
People go to the Ministry of Health and still find it difficult to get information; even the name of it is confusing, it is known as carer relief, respite care or carer support, she said.
"I have worked in this area for quite a few years and I'm still confused about it."
Getting the subsidy for people over 65 was relatively straightforward, but for under-65s the process was not the same.
"You have to go through a needs assessor in order to get this funding. If they're not clear about it, or people who need it are not clear about it, then it doesn't happen.
"I think even some GPs are confused about the whole system."
The subsidy can be paid to people such as friends, some family members, or neighbours, who temporarily care for sick or disabled people to give their usual carer a break.
It can also be paid to formal carers, such as rest-homes.
Informal carers are paid $75 a day and formal carers $85 a day.
Board regional manager planning and funding David Chrisp has previously said he was not sure what was causing the drop in utilisation of carer support, but it was probably the low pay rates.
It could also reflect a social change - fewer older people with disabilities living with someone capable of being their full-time carer, he said.
It was revealed earlier in the year the board had underspent by about $1.2 million on carer support.
