MMC Benefits Handbook
Your Contributions
You can make:
  • Roth 401(k) contributions.
  • before-tax contributions.
  • traditional after-tax contributions.
  • Roth catch-up contributions.
  • catch-up contributions.
Roth 401(k) contributions are calculated as a percentage of your eligible base pay before deductions. These contributions are included in your income for tax purposes, and the income tax withholding amounts will be deducted from the remainder of your pay, not from the contribution amount. Earnings are exempt from taxes if (1) such amounts are withdrawn when you're at least 59-1/2 (or withdrawn on account of death or total disability) and (2) you satisfy the required five taxable year period for a qualified distribution. The five-year period begins upon the earliest of the following: (i) your first Roth 401(k) contribution to the Plan, (ii) your first in-plan Roth conversion under the Plan, or (iii) your first Roth contribution to another employer's 401(k), section 403(b) or governmental section 457(b) plan if you made a direct rollover of Roth contributions from the other plan to this Plan.
Before-tax contributions are deducted from eligible base pay before Federal income taxes, and (in most cases) state and local income taxes, are determined. By choosing the before-tax savings option, you pay no income taxes on your contributions or their investment earnings while they remain in the Plan. However, your before-tax contributions (and your traditional after-tax contributions) are included in your gross earnings for purposes of figuring your Social Security and Medicare taxes and benefits.
Some state and local jurisdictions do not recognize before-tax contributions. If you are subject to those rules, state and local taxes will be withheld based on your compensation before reduction for your contributions to the Plan.
After-tax contributions are calculated as a percentage of your eligible base pay before deductions. These contributions are included in your income for tax purposes, and the income tax withholding amounts will be deducted from the remainder of your pay, not from the contribution amount. Earnings on after-tax contributions are tax-exempt while they remain in the Plan.
You may make additional catch-up contributions and/or Roth catch-up contributions during a Plan year, above the maximum annual dollar deferral limit imposed by law, if you will be age 50 or older during the Plan year. Catch-up contributions are deducted from your pay on a before-tax basis. Roth catch-up contributions are deducted from your pay on an after-tax basis.
If you are eligible (or become eligible) to make these additional catch-up contributions and you do not waive them, your catch-up contributions and/or Roth catch-up contributions to the Plan will automatically start after you have reached the IRS annual dollar deferral limit and will stop when you have also met the annual catch-up contribution limit.
2024 Before-Tax and/or Roth 401(k) Limit
$23,000
2024 Annual Catch-up Contribution Limit
$7,500