[DFG]

The 2015 earnings limit in the year of full retirement is $41,880. Social Security will deduct $1 for every $3 over this limit. There is no limit on earnings starting the year after full retirement age.

https://faq.ssa.gov/link/portal/34011/34019/Article/3739/What-happens-if-I-work-and-get-Social-Security-retirement-benefits

[kjam22]

Good point. So you could have 3 years or so (depending on your individual full retirement age) at the 15k number, and a year at the 41k number before there is no deduction.