From 1 July 2018:

The Australian Citizenship Regulation 2016 is amended to remove concessional fees for citizenship applications made under section 21 of the Citizenship Act, for persons who have:

  • prescribed health care cards; and or
  • pensioner cards

These persons will not be eligible for a concessional application fee for Australian Citizenship of either $20 or $40.  

These applicants will pay the ordinary citizenship application fee of $285. 

Source: https://www.legislation.gov.au/Details/F2018L00734/Download