More than 800 schools will qualify for additional supports and smaller classes after they were designated as disadvantaged yesterday.
Many of these schools will receive disadvantaged funding for the first time because the Department of Education has changed the criteria for funding and has introduced a new standardised system.
This followed complaints that the old system of identifying disadvantaged schools - which focused largely on employment levels - was out of date.
The 840 schools include 640 primary schools (divided equally between rural and urban areas) and 200 second-level schools.
Broadly, the schools recognised as disadvantaged are those where a large number of families are medical card-holders or are in receipt of social welfare payments. Second-level schools with high drop-out rates after Junior Cert also tend to qualify.
Minister for Education Mary Hanafin said no school would lose out because of the changes.
The Irish National Teachers' Organisation has welcomed the changes, saying they would bring "badly-needed co-ordination to measures to combat educational disadvantage".
The new system is being introduced under an action plan for educational inclusion, "Delivering Equality of Opportunity in Schools", which aims to bring greater coherence to existing efforts to combat disadvantage.
The 840 schools will receive a range of additional resources under the Schools Support Programme. Ms Hanafin said the aim was to "help support schools and their communities to achieve equality in terms of educational participation and outcomes in line with national norms".
Disadvantaged schools tend to have severe literacy and numeracy problems. Recent reports suggest that up to 30 per cent of pupils in poorer areas have severe literacy problems. The Minister said the new plan would focus on early childhood education, "improving literacy and numeracy standards and enhancing attendance, progression, retention and attainment".
The plan will be introduced over five years. When fully implemented, it will involve annual funding of €40 million.
Additional resources will be provided for early childhood education - for children as young as three - in some schools.
The INTO said that the 180 primary schools serving communities with the greatest disadvantage would be able to provide education for pre-school children.
The new system will also mean a maximum class size of 20 in junior classes and 24 in senior classes.
Action plan: key targets
• Smaller classes for more children in disadvantaged areas;
• Extra supports, both academic and non-academic, outside school time;
• Increased emphasis on developing literacy and numeracy skills;
• More guidance counsellors in second-level schools;
• Enhanced library facilities in targeted second-level schools;
• Greater access to alternative curricula, such as Leaving Cert Applied and the Junior Cert Schools Programme;
• Additional resources for early childhood education.