Once an individual reaches full retirement age, currently age 67 as of February 2015, there is no limit or penalty on how much a person can earn, as stated by the Social Security Administration. However, there are income earning limits prior to full retirement age.
Individuals may begin collecting early retirement benefits at age 62. As of 2015, for any year prior to full retirement age, the earnings limit is $15,720, according to the SSA. For every $2 earned after that, the benefit reduces by $1. In the year the person turns full retirement age, the earnings limit becomes $41,880, and for every $3 earned thereafter, benefits reduce by $1 until full retirement age is reached.