This was taken from Title 13...
Â§ 121.802 What size standards are applicable
to reduced patent fees programs?
A concern eligible for reduced patent
fees is one:
(a) Whose number of employees, including
affiliates, does not exceed 500
(b) Which has not assigned, granted,
conveyed, or licensed (and is under no
obligation to do so) any rights in the
invention to any person who made it
and could not be classified as an independent
inventor, or to any concern
which would not qualify as a non-profit
organization or a small business concern
under this section.
It basically says that the combined interest, at the time of filing, cannot exceed 500 employees, if non-profits are not involved. For most people here, this is well beyond their scope. I would say 99% of all independent inventors qualify as small entities.
It can get a little dicey for those who have entered into some agreement prior to filing. This may
include pre-employment agreements. See Hey, can my employer gank me for my invention??!
An older standard was based on yearly income generated by the applicant (where $1,000,000 was the cut-off, I believe).