It isn't true.
This is just the % of people who don't pay income tax. This has commonly been in the 40% range, and even includes some millionaires who have significant tax breaks.
Of those who don't pay income tax, 10.3% of the population (or over a fifth of those not paying income tax) are elderly. Another 6.9% make under 20,000 a year. The remainder (28.3%) still pay payroll taxes and thus contribute to the federal revenue.
Add it up and you come up with .9% that don't fit any of the criteria, and are most likely leeches. I've met some of those people, and heard of more. They aren't common, but they are out there. They live off food stamps, make no effort to seek real employment, and live in squalor waiting for handouts. They leech off family and friends who visit them (which in turn leads to no one visiting them after not too long).
But those people aren't as common as many people would have you think. I've worked in soup kitchens and homeless shelters, and I have seen many hard working, decent people come through those doors. I've talk to them about where they work and how they want to improve their lot. The are unfortunate not just in their circumstances, but in that they share the tarnish of the worthless leeches who walk through those same doors with their hands open and their minds closed.