Two 403B accounts; can I claim both?

I work for a university.  It is mandatory that after age 35 5% of your income is put into a pretax 403B.  The university then matches that account.  In addition to that account your can elect to put an additional amount of your income into a second pretax 403B account.  My W2 lists the first mandatory account under section 14 and it's labeled MNBSE.  My second, elective account is listed under section 12b as E.  My question is can I claim the amount of both accounts towards the retirement plan contribution credit?