The state specifically targets second, third and fourth grades, the year before middle school and the last year of middle school for retention. It does not prohibit retention in other grades, nor does it preclude retaining students more than once.
Intervention programs must be offered for students in grades 2-9 who have been recommended for retention and students in grades 7-12 who do not demonstrate adequate progress toward passing the California High School Exit Exam.
The state pays $3.68 per student per hour for intervention, which must be offered during the summer or when students are "off-track," as well as before and after school. Although the programs are mandatory for at-risk students, some students manage to get around the system.
If the ban on social promotion is having any impact statewide, it's difficult to tell. The state is not required to keep records, nor does it get funding for that purpose.
For some large urban districts, the retention rate has stayed fairly constant. In Los Angeles Unified the number of retained students hovered around 30,000 students between 2000 and 2005. In Fresno Unified, approximately 1,400 students were retained in 2000, compared with nearly 1,200 students in 2005. In San Diego, 4,400 students were retained in 2000 as opposed to 4,000 in 2002-03 (the latest figures available). Elk Grove had nearly 500 retentions in grades K-6 in 2003-04 versus fewer than 150 in 2004-05. Retentions have also decreased in the seventh grade.
Where there are significant reductions, effective intervention programs are given much of the credit.