Answers · Life after Optional
Can I work part-time after reaching Optional?
Short answerYes. Part-time work after Optional doesn’t undo Optional. It lowers the target number you need to hit and pulls the date closer. Every $1,500 a month of part-time income shrinks your Optional Number by roughly $450,000.
If you’d enjoy some work forever, you don’t need to save for a life that has none. Below: a live calculator, a case study, and the formulas showing what part-time income is worth against your Optional Number.
Try it live
See what part-time income does
Type your real numbers. Slide part-time monthly income from $500 up to $3,000. The calculator shows the full Optional Date, the Partial-Optional Date, and how much closer the target moves.
36%
Funded (full Optional)
Years to Optional (with part-time)
OCT 2034
vs full Optional APR 2038
Pull-forward: 42 months sooner
Part-time income after Optional (monthly)
Full Optional target
$1.80M
Partial Optional target
$1.35M
Reduced target
-$450K
A meaningful pull-forward. Part-time work makes Optional several years closer.
Assumes part-time income continues indefinitely after Optional. If it stops later, model that as a Life-After-Optional scenario in the Lab.
Assumes a 7% average real return (after inflation) and a 4% withdrawal rate.
Plain-language
Why part-time income counts as savings
The Optional Number is set by one question: how much do you need invested so that a 4% withdrawal covers your yearly spending forever? At $60,000 of spending, that’s $1.5M. At $40,000, it’s $1M.
Now suppose you’ll bring in $18,000 a year part-time. The portfolio doesn’t have to cover the full $60,000 anymore; it only has to cover $42,000. The math above collapses that into a target of $1.05M. Nearly half a million dollars less to save, for a few hours of work you’d probably enjoy.
The rule is stark: every dollar of ongoing income is worth 25 dollars off your target. It’s the same rule the Trinity Study runs in reverse.
Worked example
What part-time work saves you
Case study — Chen, 52 — late career, close to Optional
Chen has $650,000 in her 401(k) and brokerage. She saves $1,800 a month and spends about $72,000 a year. She's thinking about semi-retiring: a few consulting projects a year for the next decade, bringing in about $1,500 a month. She wants to know if she can pull Optional closer.
Balance
$650,000
Monthly save
$1,800
Annual spend
$72,000
Part-time
$1,500/mo
Full Optional target: $1,800,000 (25 × $72,000). She’s 36% funded today. Optional lands about 15 years from now, at age 67.
Partial Optional target with consulting: $1,350,000 (25 × $54,000). Optional lands about 11 years from now, at age 63 — roughly 4 years sooner. Same balance, same savings. Just a different target.
The key insight: Chen isn’t “working during retirement.” She’s working at Optional. The $1,500 a month doesn’t reduce her lifestyle; it means her portfolio only has to fund the other $54,000 of it. That’s the whole difference between a stop date and an unlock date.
From the app
This decision, inside Project Optional
The same math runs in the Scenarios Lab’s Life-after-Optional tab. Layer on side income, model when it starts and ends, and see how the Optional Date moves.
Under the hood
Assumptions and formulas
Same engine as the rest of Project Optional. Nothing is hidden.
Full Optional Number = Annual Spending ÷ 4%
Partial Optional Number = (Annual Spending − Part-Time Income) ÷ 4%
Or in plain words:
Every $1 a year of part-time income ⇒ $25 less needed in the portfolio.
- 7% average real return. Already inflation-adjusted.
- 4% safe withdrawal rate. Adjustable inside the app; fixed at 4% on this page.
- Part-time income continues indefinitely after Optional. If it stops later, model that as a Life-After-Optional scenario in the Lab.
- Income is post-tax and net of any work expenses. If the $1,500/month is gross, discount for taxes before entering it here.
- No Social Security. If you’ll claim, factor it in as additional post-Optional income.
Common questions
What people ask about this
What counts as part-time? Anything the calculator can treat as recurring monthly income. Consulting, teaching, a small business, a rental you’d keep managing, seasonal work — if you’d expect it to continue, it counts.
What if I’m not sure it’ll last? Model two scenarios: the one where it does, and the one where it doesn’t. Save both in the Scenarios Lab and compare. The honest answer for a lot of people is somewhere in the middle.
Does this change how much I have to save now? Not directly — you still contribute what you contribute. What it changes is the number you’re aiming for. That number lands sooner, and once you cross it, work is optional.
Optional vs retirement
Work Optional isn’t the same as retirement.
Retirement says: work until you can afford to stop. Optional says: work until you can afford to choose. The math is the same: enough invested to fund your yearly spending indefinitely. The story around the number is completely different.
At Optional you have flexibility. Stay in the job you like. Drop to part-time. Move to a lower-paying role you’d enjoy more. Take a year off. Start something that pays nothing for its first three years. Or keep working the same job and never touch the money, because you’d rather have the option than the exit.
That’s what “Optional” means in Project Optional. Not a stop date. An unlock date: the day the money side of your life stops requiring the exact job you have now.
Real-life limits, what we don’t model yet
The projection shows growth. It doesn’t yet model the drawdown.
Project Optional projects your investments growing toward the number that funds your yearly spending. Pulling that money out is the last mile, and it has real-world limits worth naming:
- Taxes. Traditional 401(k) and IRA withdrawals are ordinary income (usually 10 to 24%). Taxable brokerage pays capital gains (0 to 15% for most). Roth withdrawals are tax-free once vested. Which account you pull from changes the take-home number, sometimes by a lot.
- Age limits. Traditional accounts carry a 10% penalty on withdrawals before 59½, with narrow exceptions like the Rule of 55 and SEPP. Roth contributions can come out anytime; earnings can’t until 59½ and a five-year hold. If your Optional Date lands before 60, sequencing matters.
- Fees. A 1% expense ratio subtracts a full 1% from your projected 7% real return, and it compounds. Over 30 years, that often eats 20 to 30% of the ending balance.
Tax-aware drawdown sequencing (the “which account do I pull from first” question, with age gates and RMDs baked in) is on the Project Optional roadmap. Today, Optional means enough invested to fund your yearly spending indefinitely. The withdrawal plan comes next.
Ready to run your own numbers?
Save this plan and see it next to your real numbers
Type your actual numbers into Project Optional, turn on the Work-for-fun scenario in the Scenarios Lab, and stack it against every other decision at once.
Nothing here is advice.
Project Optional is a modeling tool, not a financial advisor. Real markets don’t grow at a smooth 7% every year. Real spending doesn’t stay flat. Real lives have surprises no calculator sees coming. Use what you see here to think through your options, not as a replacement for talking to someone qualified when you’re about to make a big decision.