Complex sentence: The Free File Alliance is a group of companies that work with the United States Internal Revenue Service to provide free electronic tax filing services to filers with an adjusted gross income of $54,000 or less.
Split into simpler sentences: The Free File Alliance is a group of companies who work with the United States IRS to provide free electronic tax filing services. Participants in the Free File program must have an adjusted gross income of $54,000 or less.