obavezan

1. compulsory; mandatory; obligatory
   Osnovno obrazovanje je obavezno za svu decu. — Primary education is compulsory for all children.
   Za ulazak je obavezna lična karta. — An ID card is required for entry.
2. (of a person, + da) obliged; obligated
   Poslodavac je obavezan da vam isplati platu. — The employer is obliged to pay your salary.

In the sense 'obliged to do something' it is usually followed by da + present tense.