Each year the U.S. government adjusts the limits for qualified plans and Social Security to reflect cost of living adjustments and changes in the law. Many of these limits are based on the "plan year" as defined in the plan document. The elective deferral and catch-up limits are always based on the calendar year.
Benefit Plan Limits for 2017 & 2018 Retirement and Welfare Benefit Plans
The following chart shows the major 2017 and 2018 benefit plan limits and thresholds.
If the applicable limit/threshold increased for 2018, the 2018 amount is shown in boldface.