The lower limit is $18,240 in 2020 and it applies to everyone who is below the full retirement age (also known as FRA and currently 66) for all of the year. For these people, benefits are reduced by $1 for every $2 in earnings over $18,240.
The upper limit, $48,600 in 2020, covers anyone who reaches full retirement age in that year and is only applied during the months prior to the month when the beneficiary attains FRA. For these people, benefits are reduced by $1 for every $3 in earnings over $48,600.
Updated December 16, 2019