While the new rules appear to allow a 125 plan to be used in conjunction with an ICHRA, unfortunately, I'm not sure an ICHRA would work in this specific case since it sounds like there is only one PT employee and FTEs are still offered traditional group health coverage. The new regulations appear to require a minimum class size for some classes including FT & PT when traditional coverage is offered to an applicable class. Since the minimum number of employees in the class (that must be offered) starts at 10, a class size of 1 would not work. Interested if anyone has a different take.
The other caveat is that if this employer happened to have 10 PTEs in the PT class, the employees would only be able to use the 125 for off-exchange plans. The 125 cannot be used for on-exchange plans.
Also interested if any companies are considering offering an ICHRA in 2020 or 2021.