The Government has announced the four life-shortening conditions that will allow people impacted by them early access to their KiwiSaver funds.

Anyone with Down syndrome, cerebral palsy, Huntington's disease or fetal alcohol spectrum disorder will from March now be able to access their funds earlier than 65 as life expectancy is lower than other people.

The initiative was spurred by Auckland man Tim Fairhall - with support from his mother, Joan - who has Down syndrome.

The Herald first reported Tim Fairhall's plight in 2018 after he had saved up $8000 in his KiwiSaver account from his supermarket job and always dreamt of visiting his brother overseas.

The pair fought for changes to KiwiSaver rules and got exactly that in 2019 with a law change.

Today, Commerce and Consumer Affairs Minister David Clark confirmed the four conditions that would qualify for the rule change and also the date from which the regulations under the KiwiSaver Act 2006 come into effect - March 26.

As well as the four conditions, Clark said there would be an "alternative withdrawal process" in place for those with other congenital life-shortening conditions.

"People with these conditions are automatically entitled to apply to withdraw from their fund at a time that is right for them to retire, rather than once they turn 65.

"The conditions on the list were approved because they are known to shorten a person's life expectancy below 65 years," Clark said.

"For others born with life-shortening congenital conditions – these might be rarer conditions, for example – withdrawal is still available under the new provisions.

"In this case, the only additional requirement is for a medical practitioner to verify that the person suffers from a life-shortening congenital condition."

To qualify, people would have to complete a statutory declaration that their funds would be released as if they had reached 65 and that they are no longer eligible to receive any further contributions together with medical evidence verifying their life-shortening congenital condition.

Clark said the list of conditions was developed in consultation with health and disability experts and were expected to form the majority of applications under the new withdrawal category.

"However, the flexibility exists for the Government to review the list periodically in consultation with experts to ensure it is up-to-date."

Clark today labelled the Fairhalls as "fearless advocates" for their work.

"The announcement today is a further testament to Tim and Joan's work. It's only right that the KiwiSaver scheme is fairer for everyone, and the Government has made changes to ensure that happens."

Joan Fairhall told the Herald her son knows he has made a difference to many people and is pleased for them.