Bend Points (Social Security)
Bend points are the dollar thresholds in the Social Security Primary Insurance Amount formula at which the replacement percentage applied to a worker's Average Indexed Monthly Earnings changes, creating a progressive benefit structure that replaces a higher fraction of earnings for lower-wage workers.
Bend points are among the least understood but most important structural features of Social Security benefit calculation. They are the mechanism through which the U.S. Social Security system achieves its redistributive goal: replacing a larger share of pre-retirement income for workers who earned less during their careers than for workers who earned more.
The PIA formula has two bend points, dividing the AIME into three segments. For 2024, the first bend point is $1,174 and the second is $7,078 per month. The formula applies a 90% replacement rate to the portion of AIME below the first bend point, a 32% rate to AIME between the two bend points, and a 15% rate to any AIME above the second bend point. The resulting weighted sum is the PIA.
As a concrete example, a worker with a monthly AIME of $3,000 in 2024 would have their PIA calculated as: 90% of $1,174 ($1,056.60) plus 32% of the remaining $1,826 ($584.32), totaling approximately $1,641 per month before rounding adjustments.
Bend points are updated each year by the SSA in proportion to changes in the national average wage index, so the thresholds grow gradually over time to keep pace with general wage growth. A worker whose record is finalized in a higher-wage year benefits from higher bend points, which tends to maintain the purchasing power equivalence of benefits across birth cohorts.
The 90% replacement rate on the first segment of AIME is the most notable feature of the formula. For a worker whose entire career earnings were below the first bend point, Social Security would replace 90 cents of every dollar of indexed monthly earnings — a replacement rate that substantially exceeds what higher earners receive at the margin. This design element reflects the program's dual role as both a retirement income system and a social insurance program that provides a meaningful income floor for low-wage workers.
For high-income workers whose AIME substantially exceeds the second bend point, the marginal Social Security benefit per additional dollar of lifetime earnings is quite low — just 15 cents per dollar. This explains why Social Security often represents a smaller share of retirement income replacement for high earners than for moderate or low earners, reinforcing the need for supplemental retirement savings through 401(k) plans, IRAs, and other vehicles.