The coalition will crack down on parents who refuse to vaccinate their children by holding back on family support payments.
Under the government's "No Jab, No Pay" program, Family Tax Benefit Part A payments will cop a fortnightly $28 reduction for each unvaccinated child from Sunday.
"Immunisation is the safest way to protect children from vaccine-preventable diseases," Minister for Social Services Dan Tehan said in a statement.
"Parents who don't immunise their children are putting their own kids at risk as well as the children of other people."
The government provided $14 million towards free "catch-up" vaccinations in its 2017 budget.
Exemptions have been allowed for children assessed to have natural immunity or for whom vaccinations may prove harmful.