The maximum yearly contribution for a 401(k) plan as of 2015 is $18,000 for a traditional plan, Fidelity Investment states. For those who are 50 or older, the catch-up annual contribution limit is $6,000.
The IRS decides 401(k) contribution limits, and there are lower limits for SIMPLE 401(k) plans, the IRS notes. For those plans, a $12,500 annual contribution with a $3,000 annual catch-up limit is mandated. To adjust for the cost of living, the IRS may increase the contribution limits of any retirement plan in future years. Some employer-sponsored retirement plans may have other contribution limits, Fidelity Investments notes.