Australian Governments have an opportunity to make a huge positive difference in the lives of the young people who grow up in its care. All that is needed is one simple change.

Think of your own kids. Think of them crossing that rushing river from their teenage years into young adulthood, and all the hopes and dreams you have for them along the way.

For the 85% of those aged 18 to 21 who still reside at home, parenting doesn’t stop just because they turn 18. You might help them find a flat to rent, contribute to their course fees, or introduce them to someone who can give them a head start on their career.

However, for kids who can’t grow up in the care of their parents — that is, the many thousands who grow up in state care without the social emotional or domestic “capital” of their own family — this shift from teenager to young adult has a different trajectory. It is a precarious time with often disastrous outcomes.

It’s not their fault, but it’s their burden to bear.

There are various ways to measure the weight of this burden, but here is a taste: more than a third of those young Australians transitioning from state care will exit straight into homelessness. A new report by Deloitte Access Economics has found they make up two-thirds of the homeless population under 25. More than a quarter will be hopelessly unemployed. Half will present at an acute mental health service and, tragically for this group, they will be seven times more likely to take their own lives compared to others the same age.

This group is arguably the country’s most disadvantaged cohort under 25. Fix it for this group and the government will kick a big dent in homelessness, correctional cases, youth suicide and intergenerational care statistics – notwithstanding the savings to its bottom line.

All Australian state and territory governments have taken the first steps towards operating like a good parent, by formally extending foster care supports from 18 to 21. This was a signature achievement of the national Home Stretch campaign to date. This simple act has made an extraordinary difference to these fragile lives and the way they face their young adulthood.

However, while this reform has been powerful, rates of homelessness and unemployment remain scandalously high. Their mental health suffers and too many of their babies are coming into care. Extending care alone was never going to eliminate all the challenges faced by foster kids and others in state care. It was never the summit of the mountain; it was to establish a foundation to build policy and pathway for this marginalised group.

So, in the absence of the “family social capital” enjoyed by most of those aged 18 to 21, what could our governments — as the legal parent of those in out-of-home care — do to strengthen this transition into adulthood? Could states better use their resources to help care leavers further, in the way that other parents would for those in this age group?

Overseas, governments have moved towards this approach as they cast an eye downstream to the over-prevalence of the care leaver on the beds and benches of hospitals, homeless refuges and prisons due to the poor transition out of state care.

These governments have assertively expanded the concept of the “corporate parent” by legislating post-care support for this group in a whole-of-government approach with accountability. This brings the care leaver directly in touch with the services of the important housing, health, employment and education departments. It makes the needs of care leavers a priority for those departments and sees the government responsibly acting on the principles of in loco parentis – “in the role of the parent”.

The UK Government has given this strategy such importance that it has appointed a special adviser to help develop policy to meet the critical needs of this group – Mark Riddell, who will be in Melbourne this week to share what he has learned along the way at the National Home Stretch Symposium.

This approach comes with impressive results. Around half of Californian care leavers now attend university. Similar improvements are witnessed in areas of Europe, and homelessness among care leavers has been dramatically reduced in parts of the US by providing housing stock for those leaving out-of-home care.

If Australian jurisdictions also acted this way, what could this approach look like?

Governments might follow the Northern Hemisphere and legislate to rally key departments around this group, rather than leaving it to human services departments to act for the care leaver. Put simply, those coming out of state care would be granted a special status, that accesses a whole-of-government approach to make their lives better. Departments would put together a package of benefits ranging from subsidising their education to providing employment opportunities, prioritising mental health care or allocating housing.

We know the case stacks up financially. New analysis by Deloitte Access Economics found that both the state and Commonwealth Governments will essentially double their money by investing in a suite of post-care supportive measures such as health, housing, education, employment and training. The research found this investment would lead to several billion dollars in savings, as well as halving homelessness among this group, increasing higher education participation by 2.5 times, and improving their mental and physical health – all while reducing costs to government services.

Governments across the country have all issued heartfelt apologies for the wrongs and hurts that those in care have experienced. But the measure of such apologies is the action the state takes for those in its care to ensure they have the best start in life.

Now that would be acting like a good parent should.