Free off-peak travel for elderly people under the SuperGold card is set to exceed its annual $18 million budget and the Government is looking at ways of reining it in which may impact on services.

A Transport Ministry/NZ Transport Agency discussion document released today suggests changes, including reducing the rate that providers are reimbursed; capping reimbursement payments; changing what services are eligible and removing or reducing payments for administration costs.

Transport Minister Steven Joyce said the review was always planned once the scheme, which started in October 2008, had run for a while.

The scheme would be kept but changes were needed.

"The highest priority of the review process is to consider how to keep the scheme within the available budget of $18m a year, while continuing to provide improved mobility for older people."

Officials would look at how "off peak" should be defined and consider eligibility of certain high cost services - including the Waiheke ferry and the train service between Wellington and the Wairarapa.

"The transport concession of the SuperGold card has an annual budget of $18 million dollars across the country - $2 million of that is currently spent on the Waiheke ferry alone," Mr Joyce said.

Key stakeholding groups will be consulted.