If I sell an invention idea to a company, do I lose monthly SS benefits? Thank you, Nora.
Your question pertains to Social Security's Earnings Test, which ends once you reach full retirement age. Moreover, if you lose benefit X before full retirement age to the Earnings Test, benefit X will be bumped up at full retirement to credit you, on a full actuarial basis, for benefits lost due to the Earnings Test.
My sense is that the proceeds from the sale of an invention would count as self-employment income. Please read the first of the three horror stories discussed at http://www.pbs.org/newshour/making-sense/column-3-true-social-security-h.... The story is potentially very pertinent to your situation.