Familes who send their children to private school are to receive a share of e90 million (pound;63m) in cashback incentives.
It is the latest attempt by Silvio Berlusconi's centre-right coalition government to fulfil its pledge to revive the ailing, predominantly Catholic private sector.
Private pupil numbers have dipped below a million, a loss of more than a million in 30 years.
A law introduced last year gave private and state schools equal status, and for the first time granted private schools access to public funds, for example to run teacher-training courses.
The cash incentives were earmarked for families earning less than e30,000, but this restriction has been lifted. Spread over three years, the money is to be divided equally among parents, regardless of income.
It is not known how many families will take up the offer, but the Milan daily newspaper Corriere della Sera predicted the payments will be around several hundred euros - less than a 10th of the average e3,500 annual fees charged by Italy's private schools.
Opposition leaders claim the payments are illegal, since the 1948 constitution states that private schools can exist only if they are not a "financial burden" to the state.