If you perform all the work for the enterprise, even if that is fewer than 100 hours, you qualify to materially participate.
Learn more reports this explanation of material participation.
You "materially participate" in a business if you do any of the following:
--Work more than 500 hours in the year, or between 100 and 500 hours in certain cases, OR
--Perform all the work, even if you work fewer than 100 hours, OR
--Worked actively for five of the last ten years (they do not have to be consecutive) or three years if it was a personal service, such as consulting
A broader discussion of the topic including the seven IRS material participation tests may be found here.