Final answer:
The official US Code is updated biannually with supplements published annually.
Step-by-step explanation:
The official United States Code is updated and published every six years, with supplements published in between the full updates.
The full updates to the US Code occur biannually, whereas the supplements are updated and published annually. Therefore, the correct answer to how often the US Code is updated and published is, it is fully updated biannually with annual supplements.