How a Roth IRA actually works — the mechanic, not the marketing

A Roth IRA is not an investment. It is a wrapper. Inside the wrapper you put investments — index funds, bonds, a single embarrassing meme stock, whatever — and the wrapper changes how those investments get taxed. That is the entire product. Everything else is marketing.

The plumbing, in plain English

Here is what actually happens when you put $1,000 into a Roth IRA in 2024.

You earned that $1,000 at your job. It showed up on your W-2. You paid federal income tax on it, you paid state tax on it, you paid FICA on it. What lands in your checking account is the after-tax residue. You then move some of that residue — say, $1,000 — into a brokerage account you have designated as a Roth IRA at Fidelity or Schwab or Vanguard.

That $1,000 sits there and, if you do nothing, earns roughly nothing. So you buy something with it — let's say VTI, a total US stock market ETF. Now you own $1,000 of VTI inside the wrapper.

Over the next 30 years, that $1,000 grows. If it compounds at a 7% real return, it becomes about $7,600. When you are 59½ and you sell the VTI and pull the money out, you pay zero federal tax on any of it. Not on the original $1,000, not on the $6,600 of gains. Zero.

Compare that to the same $1,000 in a regular taxable brokerage account. Same VTI, same 30 years, same $7,600. But when you sell, you owe long-term capital gains tax on the $6,600 of appreciation — 15% for most people, so roughly $990 to the IRS. Plus you paid tax on every dividend along the way.

That is the mechanic. You pay tax on the seed. You do not pay tax on the tree.

The limits are smaller and weirder than you think

For 2024, you can contribute $7,000 to a Roth IRA if you are under 50, or $8,000 if you are older. That is the ceiling across all your IRAs combined, not per account. Open five Roth IRAs at five brokerages if you want; the IRS still only lets you put $7,000 in the collective bucket.

You also have to have earned income at least equal to what you contribute. Unemployed people cannot fund a Roth from savings. A working spouse can fund one for a non-working spouse, which is the one useful exception.

Then there is the income phase-out. In 2024, if you are single and your modified adjusted gross income is over $161,000, you cannot contribute directly at all. Between $146,000 and $161,000 you can contribute a partial amount. Married filing jointly, the phase-out runs $230,000 to $240,000. Above the top of the range, direct contributions are off the table — though the backdoor Roth (contribute to a Traditional IRA, immediately convert) exists as a workaround for people who like paperwork.

One feature people forget: your contributions — not gains, contributions — can be pulled out of a Roth IRA at any time, at any age, for any reason, without tax or penalty. If you put in $7,000 last year and need it next month for a medical bill, you can take the $7,000 back. This makes a Roth IRA a stealth-decent emergency fund for people who have not yet built a real one, though I would still rather you had a real one.

Roth vs. Traditional is usually the wrong question

The internet has generated approximately eight million words on Roth vs. Traditional. The framing is: pay tax now (Roth) or pay tax later (Traditional), and the answer depends on whether your tax rate will be higher in retirement than it is today.

Here is the reason that debate is mostly a waste of your afternoon: for someone with $10,000 to their name and a job that pays under $80,000, the tax-bracket math on Roth vs. Traditional works out to a difference of a few thousand dollars over a career. Meaningful, but not decisive. What is decisive is whether you contribute at all, and whether the money actually gets invested rather than sitting in a settlement fund earning 0.01% because you forgot to click 'buy.'

The better question sequence is: (1) Do you have an employer 401(k) with a match? Capture the full match first, because it is a 50–100% instant return you cannot get anywhere else. (2) After the match, does a Roth IRA make sense as your next dollar? For most people early in their earning years — when their tax rate is genuinely low — yes. Pay tax at 12% or 22% now rather than gambling on what rates will be in 2055. (3) Only after you are maxing the Roth does going back to fill the 401(k) up to the $23,000 limit become the next move.

If your HR person or a bank rep tries to steer you toward something more complicated — a variable annuity, a whole life policy, an IRA at a full-service broker charging 1% — the reason they are pushing it is that those products pay them a commission and a Vanguard Roth IRA does not. Say this:

"Thanks, I want to keep my retirement accounts at a discount brokerage with no advisory fee. I'm not looking for a managed product."

Then leave.

What to actually do this week

If you have $500 to spare and a pulse, open a Roth IRA at Fidelity, Schwab, or Vanguard. It takes about 12 minutes online. Fund it from your checking account. Then — and this is the step people skip — actually buy something with the cash. A total-market index fund (VTI, FZROX, SWTSX depending on the brokerage) is a defensible default. If you contribute $7,000 a year from age 25 to 65 at a 7% real return, you end up with roughly $1.4 million, tax-free, from a wrapper most people never bother to open.

Go open the account now. The rest of the money decisions can wait until tomorrow; this one takes 15 minutes and stops being available on December 31 for this year's contribution limit.