http://admission.universityofcalifornia.edu/transfer/general-education-igetc/igetc/index.html says that IGETC for UC requires 34 semester units, distributed as listed in the table on that page. If you want to apply to a CSU with IGETC completed for CSU, then you do need to add the oral communication course.
Will your community college certify IGETC for UC only for you?