By Dr. James M. Dahle, WCI Founder

There seems to be a wide misunderstanding among investors and their advisers alike about the merits of saving for retirement using a plain old 401(k). I hear too many statements like “Tax rates are going up, look at the national debt. Why pay taxes later when you can pay them at today's rate?” This misconception causes too many people to make bad decisions, such as contributing to a Roth account preferentially in their peak earning years or worse, not maxing out a 401(k) in order to invest in a taxable account or cash value life insurance. Investing in a 401(k) is like getting a match from Uncle Sam. There are three ways that contributing to a 401(k) lowers your taxes.


#1 Up-Front Tax Deduction

The most significant way that a 401(k) saves you taxes is the upfront tax deduction you get in the year you make the contribution. For example, if my marginal tax rate were 32%, and I contributed $10K, I would save $3,200 on my taxes that year. Critics of the 401(k) argue that you're just delaying the taxes. Even if that were true (it usually isn't as we'll see shortly), that delay on paying taxes is still valuable.

There is a concept called “the time value of money” which basically says that money now is worth more than money later. This is especially true when you consider how our financial lives work. When did you really need some extra cash?

  • In your 20s, when you had big tuition bills and needed a car.
  • In your 30s, when you needed money for a downpayment, some furniture, student loans, and a bigger car.
  • Perhaps even in your 40s, when the kids start into college.

The fact is that a relatively small amount of money early in life can often be far more valuable than more money later in life. Plus, if the US Government collapses, at least you enjoyed your 401(k) tax break before it did!


#2 Tax-Protected Growth in a 401(k)

In a taxable account, the dividends and capital gains distributions that your investments kick out each year are taxed. When you sell an investment with gains you also have to pay taxes. Dividends and capital gains are generally taxed at a rate lower than your marginal tax rate, but the drag on your returns can still be significant. For example, an investment that gains 8% with a yield of 2% taxed at 15% only grows at 7.7%. On a $100K investment that drag totals $26K after 20 years. In a 401(k) that tax drag is eliminated, allowing faster accumulation of your nest egg.


401k lowers taxes

#3 Tax Rate Arbitrage

When you contribute to a 401(k), you save taxes at your marginal rate, for example, 32%. This is the rate at which the last dollar you make is taxed. However, when you withdraw money from your 401(k), especially if you don't have a pension or other taxable income and haven't started taking Social Security, the money will be taxed at a far lower rate. It is taxed at your “effective” tax rate.

As an example using the 2020 tax year brackets, if you're retired at 60, married, taking the standard deduction, and have no taxable income then:
  • The first $24,800 you pull out of your 401(k) comes out tax-free (due to 2020 standard deduction).
  • The next $19,750 is taxed at 10%.
  • The next $60,500 is taxed at 12%.

So you can actually pull $105,050 out of your 401(k) that year and you only have to pay $9,235 in taxes, for an effective tax rate of less than 9%. Saving taxes at 32% and paying them decades later at 9% is a winning formula.  Even if you needed more income from your 401(k), the next $90,800 you pull out is taxed at 22%. The effective tax rate of withdrawing a total of $195,850 ($105,050 + $90,800) is just less than 15%.


The bottom line? If you're in your peak earning years, most of the time you should max out every tax-deferred account available to you, including 401(k)s, 403Bs, 457s, HSAs, SEP-IRAs, Solo 401(k)s, profit-sharing plans, defined benefit plans, etc. You can still get tax diversification by using a personal and spousal backdoor Roth IRA rather than the Roth option in your 401(k) or 403B and perhaps by doing a few Roth conversions in low-income years just before or after your retirement date.

What do you think? Are you using a 401(k)-like account to save for retirement? Why or why not?