Almost half of Australia's superannuation fund members do not know they are insured for total and permanent disability (TPD), according to a survey commissioned by law firm Slater & Gordon.

A survey of 1047 people found 47 per cent had not heard of TPD insurance cover, as offered through superannuation funds.

"The knowledge rate was lowest amongst people aged between 18 and 34, with 61 per cent unaware," the law firm said.

In most cases, TPD insurance is included as a default cover when members join a superannuation fund.

The low awareness meant members were missing out on payments that could assist them if they were ill or injured, Slater & Gordon superannuation national practice group leader Dina Tutungi said.

"Knowing that you have insurance cover to assist you in these circumstances is important for your peace of mind and can help relieve the financial pressure that comes from a decreased capacity to work," Tutungi said.

Only 29 per cent of respondents were aware the majority of super funds automatically deducted money to cover them in the event they suffered a total or permanent disability.

TPD insurance premiums paid by Australian workers usually ranged from $50 to $480 a year, with premiums automatically deducted from superannuation accounts, Tutungi said.

"The results of our survey clearly point to a need for some greater education around these issues, however, in the meantime we would urge all Australians with superannuation funds to carefully check their statements to see if they are covered," she said.