As of 2015, the annual contribution limit for traditional 401(k) plans is $18,000, as stated on the Fidelity Investment website. For contributors age 50 and older, the annual catch-up contribution limit is $6,000.
401(k) contribution limits are decided by the IRS, which states that there are lower limits for SIMPLE 401(k) plans. Those plans allow a $12,500 annual contribution with a $3,000 annual catch-up limit. The IRS may increase the contribution limits of any retirement plan in future years to adjust for cost of living. According to Fidelity Investment, contribution limits may differ or be restricted with some employer-sponsored retirement plans.
In addition to an individual's contributions, an employer may also contribute up to $53,000 per year to an employee's 401(k) and up to $59,000 per year for employees age 50 or older, advises the IRS. The total employer contribution cannot exceed the employee's total compensation for the year.