Are the OPT visa durations for corporate LLM programs typically one year plus OPT, and is a three plus three OPT visa valid in USA?

OPT (Optional Practical Training) for corporate LLM programs in the USA is typically 12 months. All F-1 graduates are eligible for this standard OPT period, which allows practical experience related to your field of study.

A "three plus three" OPT arrangement is not valid. OPT is limited to 12 months per degree level, and LLM programs do not qualify for the STEM OPT extension.