As part of the expansion, the Early Action Task Force will increase the support it gives to organisations across the UK to deliver preventative services to under-18s.
Measures include training on early intervention approaches for small voluntary groups, and more research into ways to avert mental ill-health, housing difficulties and unemployment.
The task force will also carry out an audit of its 650-plus member organisations to find ways to better involve them in early intervention work with children, young people and adults.
The expansion is being paid for by a £498,000 Big Lottery Fund grant to Community Links, the charity behind the task force.
David Robinson, chair of the task force, said the three-year grant will help embed preventative work across the country: "Thanks to this National Lottery grant, we can take early action from common sense to common practice.
"It's hard for charity leaders to find the time to think preventatively when we're battling to tackle increasingly complex social issues. But it is precisely because frontline needs have become more complex that we need to think preventatively."
The money will also enable the task force to step up its efforts to influence local and national policy and encourage funding organisations to create programmes that bankroll early intervention projects.
"Since launching, the Early Action Task Force has made a significant impact - both locally and nationally - and this new funding will drive its work forward," said Joe Ferns, the UK funding director at the Big Lottery Fund.
Community Links founded the UK-wide task force in January 2011. The task force's work is due to continue until 2021.
Community Links is a charity that supports communities in London and is part of the Catch22 group of charities.