135.243 (a)(1)
Of a turbojet airplane, of an airplane having a passenger-seat configuration, excluding each crewmember seat, of 10 seats or more, or of a multiengine airplane in a commuter operation as defined in part 119 of this chapter, unless that person holds an airline transport pilot certificate with appropriate category and class ratings and, if required, an appropriate type rating for that airplane.

So I'm curious as to how people are interpreting 135.243(a)(1). When I read it I see reference to 3 distinct categories:
1. Turbojet airplane
2. Airplane with 10 or more pax seats
3. Multiengine airplane in a commuter operation under part 119

However, this interpretation letter from the Assistant Chief Counsel seems to think of it as only referencing 2 distinct categories:
1. Turbojet airplane with 10 or more pax seats
2. Multiengine airplane in a commuter operation under part 119

With this in consideration, if 135.243 (a)(1) is being officially interpreted as only referencing 2 distinct categories then they are saying that you DON'T need an ATP to operate a turbojet part 135 for aircraft with less than 10 pax seats! This is contrary to everything I have understood about 135 turbojet PIC requirements. I called the office and left a message and am waiting to hear back.

Even if you look at 91.1053(a)(2)(i) you will see that it makes NO reference to pax seating number requirements. Only the requirement for an ATP and Type Rating.