More than 13,000 hospital admissions of children a year were prevented by Sure Start centres before their funding was cut by the Tories, research has found.
The Institute for Fiscal Studies found that the benefits of the centres were "substantial" with children in poorer neighbourhoods getting most out of them.
Sure Start centres, which brought together health, parenting support and childcare for the under-5s, received £1.8bn a year at their 2009 peak.
But spending has fallen by more than two-thirds over the last decade under the Tories with many centres scaled back or closed.
The IFS research, funded by the Nuffield Foundation, found that the early years programme delivered long-lasting health benefits for children well into their teenage years.
And the savings from reduced hospitalisations up to age 15 offset around 31% of spending on the programme.
Maud Pecher, a co-author of the report, said: "Children who had greater access to Sure Start in their early years were far less likely to be hospitalised later on - at its peak, Sure Start provision prevented over 13,000 hospitalisations of 11 to 15-year-olds each year.
"These benefits were particularly long-lasting for boys and children in disadvantaged neighbourhoods."
Yet there was almost mo evidence that Sure Start had improved children's hospital admission outcomes in the richest neighbourhoods.
The research suggested prioritising spending on early years programmes in disadvantaged areas would make sure services are better targeted to children's health.
Early Years Alliance chief executive Neil Leitch said: "The fact that the Sure Start programme is still paying dividends for children into their teenage years is yet more confirmation of what we already know - that investing in young children is not only the right thing to do, it is also a sound financial decision.
"Recent governments have shamefully let down children and families by not only cutting Sure Start services which reduce hospitalisations, and do much more good besides, but also by allowing funding for under-five education to dwindle to far less than the cost of delivering it."
A Department for Education spokesperson said: "We recognise that the early years of a child's life are the most crucial, which is why we have put unprecedented investment into childcare over the past decade".