Four accounts run American retirement saving: the 401(k), the IRA, the Roth, and the conversion. They are not four rival products — they are two kinds of account, one tax flavor, and one move between them.
美國人的退休儲蓄，繞著四個名字轉：401(k)、IRA、羅斯（Roth）、轉換（Conversion）。它們不是四種互相競爭的商品——而是兩類帳戶、一種稅務口味、和一個搬錢的動作。
What the Names Stand For
這些名字的由來
401(k) is not a model number. It is a paragraph of the US tax law — subsection 401(k) of the Internal Revenue Code, the part that lets workers set pay aside for retirement.
401(k) 不是產品型號。它是美國稅法裡的一段條文——《國內稅收法典》(Internal Revenue Code) 第 401(k) 小節，就是允許員工把薪水撥出一部分存退休金的那一段。
IRA is short for Individual Retirement Arrangement — the IRS’s official name for a personal retirement account; most people say Individual Retirement Account. And Roth is a person’s name: Senator William Roth, who wrote the Roth IRA into law in 1997.
IRA 是 Individual Retirement Arrangement 的縮寫——這是國稅局給個人退休帳戶的正式名稱；一般人常說 Individual Retirement Account。而 Roth 是一個人名：羅斯參議員（William Roth），他在 1997 年把羅斯 IRA 寫進法律。
The 401(k): Saving at Work
401(k)：在公司存錢
A 401(k) is a retirement plan run by your employer. The money leaves your paycheck before you can spend it — saving on autopilot.
401(k) 是雇主提供的退休計畫。錢從薪水直接扣除，還沒到手就先存好——自動儲蓄。
For 2026 the limit is $24,500; at 50 or older you may add $8,000 more, and at ages 60 to 63, $11,250 more. Many employers add a match — free money; never leave it on the table.
2026 年上限是 24,500 美元；50 歲以上可再多存 8,000，60–63 歲可再多 11,250。許多雇主還會配比（match）——那是免費的錢，千萬不要錯過。
The traditional kind is pre-tax: the tax bill waits until the money comes out, and required minimum distributions (RMDs) start in your seventies. Leave the job, and the money can roll into an IRA.
傳統型是稅前存入：稅單等到提領時才來，七十多歲起要開始強制提領（RMD）。離職後，錢可以轉進 IRA。
The IRA: Your Own Account
IRA：自己的帳戶
An IRA is a retirement account you open yourself at a bank or brokerage — no employer needed. For 2026 the limit is $7,500, plus $1,100 at 50 or older, and you need earned income to contribute.
IRA 是你自己在銀行或券商開的退休帳戶——不需要雇主。2026 年上限 7,500 美元，50 歲以上再加 1,100；存入需要有工作收入。
A traditional IRA works like a traditional 401(k): maybe a deduction going in, tax coming out, RMDs later. It is also where old 401(k)s often end up, gathered in one place.
傳統 IRA 和傳統 401(k) 很像：存入時可能抵稅，提領時繳稅，晚年有 RMD。它也是舊 401(k) 常聚集的地方，集中在一處管理。
Roth: Tax Now, Not Later
羅斯：先繳稅，後免稅
“Roth” is not an account. It is a tax treatment, named after Senator William Roth: money goes in after tax, grows untaxed, and — if the rules are met — comes out tax-free in retirement.
「羅斯」不是一種帳戶，它是一種稅務待遇，以羅斯參議員（William Roth）命名：錢稅後存入、成長免稅，符合規則時，退休提領也免稅。
There is a Roth IRA and a Roth 401(k). Contributing directly to a Roth IRA has income limits; a Roth 401(k) has none. And since 2024, Roth 401(k) money has no RMDs.
有羅斯 IRA，也有羅斯 401(k)。直接存羅斯 IRA 有收入上限；羅斯 401(k) 沒有。2024 年起，羅斯 401(k) 也沒有 RMD。
The bet is simple: pay tax at today’s rate if you expect your retirement rate to be the same or higher — then never owe tax on the growth again.
賭注很簡單：如果你預期退休時的稅率相同或更高，就用今天的稅率先付清——之後的成長，永遠不用再繳稅。
Conversion: Moving to Roth
轉換：搬進羅斯
A Roth conversion moves money from a traditional IRA — or an old 401(k) rolled into one — into a Roth IRA. There is no income limit and no dollar cap, but everything you move becomes taxable income that year.
羅斯轉換，是把傳統 IRA——或轉入 IRA 的舊 401(k)——的錢搬進羅斯 IRA。沒有收入上限、沒有金額上限，但搬過去的每一塊錢，在當年都算應稅收入。
How to do it: ask your brokerage for a direct trustee-to-trustee conversion, choose the amount, and finish before December 31. You will receive a Form 1099-R, and you report the conversion on Form 8606.
怎麼做：請券商做直接轉帳（trustee-to-trustee），決定金額，在 12 月 31 日前完成。之後你會收到 1099-R 表格，並在 Form 8606 上申報這次轉換。
Three warnings. A conversion cannot be undone. The tax is best paid with money outside the IRA, not out of the amount you convert. And if your IRAs hold other pre-tax money, the pro-rata rule taxes every conversion proportionally.
三個警告。第一，轉換不能反悔。第二，稅金最好用 IRA 外面的錢付，不要從轉換金額裡扣。第三，如果 IRA 裡還有其他稅前資金，比例規則（pro-rata rule）會按比例課稅。
Then why convert? The classic window is a low-income year — after retirement, before Social Security and RMDs begin. Convert just enough to fill your current tax bracket, and not a dollar more.
那為什麼要轉？經典時機是低收入的年份——退休之後、社會福利金與 RMD 開始之前。只轉到填滿目前的稅率級距為止，一塊錢都不要多轉。
So run the numbers before you move a dollar. A conversion is income: convert too much in one year and the extra income can push you into a higher tax bracket — and it can also shrink health-insurance subsidies and raise Medicare premiums two years later. Let your tax picture set the amount, not the size of the account.
所以，搬錢之前先把數字算清楚。轉換就是收入：一年轉太多，多出來的收入可能把你推上更高的稅率級距——還可能讓健保補助縮水、讓兩年後的 Medicare 保費變貴。金額由你的稅務狀況決定，不是看帳戶有多大。
Good to Know
須知
Two clocks guard Roth money. Earnings come out tax-free only after the five-year rule and age 59½ (or another qualifying event); and every conversion starts its own five-year clock for the early-withdrawal penalty.
羅斯有兩個時鐘在把關。收益要免稅提領，必須滿足五年規則且年滿 59½（或其他合格事件）；每一次轉換，也各自啟動一個五年時鐘，關係到提前提領的罰款。
The dollar limits above are the IRS figures for 2026; they change most years. This post is education, not personal advice — before a conversion of any real size, run your own tax numbers, or sit down with a tax professional.
以上金額是 IRS 的 2026 年數字，幾乎每年都會調整。本文是知識分享，不是個人建議——做金額不小的轉換之前，先算清楚自己的稅，或請稅務專業人士協助。
Let’s Talk About It
來聊一聊
Two coworkers, one lunch break, and the accounts everybody has and nobody understands at first.
兩個同事、一段午休時間，和人人都有、一開始卻沒人搞得懂的帳戶。
Dave: Hey Lisa, quick question — are you putting money into the 401(k) here?
戴夫：嘿，麗莎，快問一下——你有往公司的 401(k) 放錢嗎？
Lisa: Oh yeah. At least enough to get the company match. That’s free money!
麗莎：有啊。至少放到能拿滿公司配比。那是免費的錢！
Dave: Free money? Come on — nothing’s free.
戴夫：免費的錢？拜託——天底下沒有白吃的午餐。
Lisa: Ha — okay, almost free. Don’t grab the match and you’re leaving money on the table.
麗莎：哈——好啦，算是免費。你不拿配比，就是把錢留在桌上不撿。
Dave: Fair enough. My old 401(k) from my last job is just sitting there doing nothing.
戴夫：有道理。我前一份工作的 401(k) 還丟在那裡，什麼事都不做。
Lisa: Roll it into an IRA. Took me twenty minutes online, tops.
麗莎：轉進 IRA 就好。我上網弄，頂多二十分鐘。
Dave: Roth or traditional? Everybody keeps throwing those words around.
戴夫：Roth 還是傳統型？大家一直把這兩個詞掛在嘴邊。
Lisa: Depends. I convert a little to Roth every year — pay the tax now, chill later.
麗莎：看情況。我每年轉一點到 Roth——現在繳稅，以後輕鬆。
Dave: “Chill later” — now that’s a plan I can get behind.
戴夫：「以後輕鬆」——這個計畫，我可以。
Lisa: Just watch your tax bracket. Convert too much at once, and Uncle Sam throws a party.
麗莎：只是要盯著你的稅率級距。一次轉太多，山姆大叔就開派對了。
