Developmental or Maintenance Bilingual Education

Purpose: To develop bilingualism and biliteracy proficiency and to achieve academically at grade level.

English language learners (ELLs) maintain and develop their native languages as they acquire English. 
Students initially receive most instruction in their native language as English is added in increasing amounts each year. By fourth or fifth grade, students receive instruction equally in both languages.

This additive program exists where there are sufficiently large numbers of students of one language background to make it possible to hire bilingual teachers and where there is interest and support in the community for having a bilingually educated population. 
  
Criticism: The main obstacles to implement this program in the Chilean education system are the necessity of having: qualified bilingual teachers and active support from ELLs and their family. 

Source:  
"IRIS | Developmental Bilingual Education". Iris.peabody.vanderbilt.edu. N.p., 2017. Web. 8 Apr. 2017.
 Soltero, S. W. (2004). Program Models For Second Language Learners. En S. W. Soltero, Dual Language: Teaching and Learning in two Languages (pág. 4-5). Pearson.