2018 Retirement Plan Contribution Limits

The IRS recently announced updated retirement plan contribution limits for 2018, and there are several significant changes taking place. Here's how the new contribution limits will affect 401(k) plans, IRA investors, and Americans who use other varieties of tax-advantaged retirement savings plans.

401(k), 403(b), 457, and Thrift Savings Plan contribution limits
For 2018, the contribution limit for employees into these types of accounts is rising from $18,000 to $18,500.
For participants who will be age 50 and older by the end of 2018, the catch-up contribution amount of $6,000 hasn't changed, meaning that older savers can choose to defer up to $24,500 of their compensation into their accounts.
Keep in mind that these limits only refer to elective deferrals. They don't include other contribution sources like employer matching contributions, nonelective deferrals, or allocations of forfeitures. Including all sources, the 2018 contribution limit for these plans is increasing by $1,000 to $55,000. This does not include the catch-up contribution, if applicable, for a possible overall maximum 2018 contribution of $61,000.

Self-employed individuals who use an individual 401(k) are considered both the employer and employee, and can contribute as much as 25% of their net self-employment income, up to the overall limit that applies to them.

In addition to the standard catch-up contribution limit, 403(b) plans can permit employees with at least 15 years of service to contribute as much as $3,000 more as part of their elective deferrals, even if they haven't reached age 50 yet. For employees over 50, both catch-up provisions can be used in many cases.
Similarly, 457 plans have their own catch-up provision that allows participants within three years of the plan's normal retirement age to contribute as much as twice the annual elective deferral limit.

Traditional and Roth IRA contribution limits
This section is pretty easy, because nothing has changed in regards to the IRA contribution limits. IRA owners can still contribute up to $5,500 for the 2018 tax year, with an additional $1,000 catch-up contribution allowed for individuals age 50 or older. Contributions for 2018 can be made from Jan. 1, 2018 through the April 2019 Tax Day.
While the contribution limits haven't changed, it's important to mention that the income limitations have changed for both the traditional IRA deduction (if covered by an employer's retirement plan) and for Roth IRA eligibility.

SEP-IRA limits for 2018
Contributions to a SEP-IRA only come from the employer, and the maximum allowable contribution for 2018 is 25% of each employee's salary up to the same $55,000 maximum that applies to 401(k) and other workplace retirement plans as discussed in the first section.
For self-employed workers, who are also permitted to use a SEP-IRA to save for retirement, the effective contribution limit is reduced to 20% of adjusted profit after subtracting the self-employment tax, as the calculation is based on net self-employment income, which removes the SEP-IRA contribution itself.

2018 SIMPLE IRA contribution limit
For 2018, the SIMPLE IRA employee contribution limit is unchanged at $12,500, with a $3,000 catch-up allowance for participants age 50 or older.