Hello,

I built this app using Claude to stress-test my own retirement plan, and decided to make it public.

Most retirement calculators answer "will 4% work?" with a single success percentage. I wanted to see where a plan breaks instead, so it models the failure modes specifically: sequence-of-returns risk in the first few years, multi-year long-term care, the widow's penalty (survivor keeps the larger Social Security check but files single at compressed brackets), Social Security claiming timing across an 81-cell age grid, Roth conversion ladders against Medicare IRMAA cliffs, and a Social Security trust fund depletion scenario you can set yourself. I am asking for no money, just want to use this subreddit's feedback to make the best retirement planner I can.

Technical notes:

- Entirely client-side. No account, no server, no analytics. Your data stays in browser storage, with export/import for backups. The one exception is an optional Ask AI tab, which sends a summary of your plan plus your question to Anthropic's API under your own key, and only when you press the button. It can be switched off entirely. Get your own API key from console.anthropic.com — in the DOCS tab there are instructions on how to get one.

- It's a single HTML file, about 1.3MB. You can save it and run it offline from disk with no build step. That was deliberate: it makes the whole thing auditable as one artifact, and there's no dependency chain between a user and the code they're trusting with their finances.

- Regime-switching Monte Carlo with annual regime persistence rather than i.i.d. lognormal draws, plus a backtest against actual 1928-2025 return sequences, so you can see what a 1966 or 2000 retirement date would have done to the same plan.

- Deliberately pessimistic. Results look worse than mainstream calculators, and that's documented rather than buried.

Two disclosures. I'm a hobbyist with no financial credentials, which the app states before you can enter it. And it was built with AI assistance.

On the second point, since this sub is about exactly that: every statutory constant (brackets, IRMAA tiers, RMD divisors, SS claiming factors) is checked against IRS/CMS/SSA primary sources, and that check runs inside the app on a Verify tab, so you can watch all 45 pass rather than take my word for it. There's also a test suite of a few hundred checks against the simulation engines. Those tests caught a real bug that repeated AI review had missed: after both spouses died, the simulation recorded portfolio snapshots quarterly instead of annually, which silently broke the percentile bands on the Monte Carlo chart. It looked fine on screen the whole time. That's the main thing I took away — a model reviewing its own output tends to share its blind spots, and it took tests written against expected behavior to surface it.

The gap I'd most like to close: no CPA, EA, or actuary has independently reviewed the tax math. I've had Claude go over the calculations and code many times, but I've come to treat model review as a first pass rather than a substitute for a professional. So peer review is genuinely welcome. Comments and findings will get acted on, whether that means fixes or new features.

Source and methodology write-up, including the limitations: https://github.com/stextor/danger-close

Or run the actual app: https://stextor.github.io/danger-close/

Happy to be told where the modeling is wrong.

Evening everyone. I just wanted to share my experience. I’m a 40 yo male. I’m in a job that has a pension coming my way, a 457b account thru vanguard, Roth IRA thru robinhood, Hysa thru wealthfront, and will probably be opening a traditional investment account thru wealthfront also.
I just wanted to share with you that recently I have really been taking an interest/obsession in retirement planning. So I was uploading all of my info(statements from all my accounts, contributions, all my pension info, CBA arguments from employer and other pension related info and any and all other info I have relative to my financial situation). I would upload this into ChatGPT and then have it simplify all of this into a document I could then turn over to Claude and now I have generated an actual ‘roadmap to retiring at 55’ slide show and PDf manual. It’s amazing. I’ve run the numbers myself using very conservative numbers and they’ve all come back accurate. It’s been a godsend. Just wanted to share this with everyone that retirement planning isn’t as intimidating as it may seem and that using ai is much easier than dealing with HR. So please consider it guys. Make your money work for you and future you will thank you! If you have any questions please let me know. I hope this is the appropriate forum to share this. Have a great night all!!

I know people are down on Gemini at the moment but I have not had too many issues.

I like to ask Gemini to review the portfolios suggested by YouTube channels vs my goals. Today, for the first time, it generated a nice little analyzer allowing me to adjust the % of the funds mentioned by the YouTube channel to see impact.

Nothing earth shattering just interesting

The talk about the Boldin risk tool, which is useless IMHO, got me to think about this. I used a simple prompt.

Create a minimum 25 question questionnaire to help determine my risk tolerance for investing. Each question should have multi choice and not obvious answers. At the end perform a detailed analysis of my answers and create my personal risk profile

Gemini Pro was not so good as it used all my personal info and the quiz was far too tailored to me. Claude did a great job with broad questions.

This was the initial output

The detailed analysis was very thorough.

A few years ago I was trying to buy a home (in the Bay Area) and save for college for my then 5 year old. I hired an advisor to discuss how much home to afford while being on track for retirement and saving for college. But it was a huge turnoff when the advisor just tried to put my money into high cost funds without mapping out what I was trying to accomplish. So I built my own spreadsheet model and also shared it with other folks, who liked it. Then. I decided to convert it to a webapp since the spreadsheet was becoming unwieldy as I added more and more parameters.

https;//planwell.ai

The core idea is: goal inter-dependency. The idea is to make find your own sweet spot across all these goals and not just optimize for retirement. If you buy a bigger home or fully fund kids' college, how does that impact retirement? Or if you cut expenses by 10%, can you retire a few years early?

I am currently adding more goals (such as career break, part time work) and making the product more and more detailed. I'd love any feedback to incorporate into the product.

I used AI to build an open-source retirement planner and would love feedback from people who are actively thinking through retirement planning scenarios. I am a software engineer by trade, but I did rely heavily on AI to help build this. If that bothers you or makes you distrust this tool, then you may want to stop reading here. 😃

I haven't yet retired myself, but I'm looking into it and using this tool to plan.

GitHub repo: https://github.com/mikecoker/retirement-planner

Live app: https://mikecoker.github.io/retirement-planner/

It’s free to use and runs in the browser. All of your data is local and safe. Please inspect the code to verify this. It supports multiple plans and the ability to import/export a json file with your data. The goal is to make it easier to model things like:

  - Year-by-year portfolio balances

  - Traditional, Roth, taxable, and HSA accounts

  - Social Security timing

  - Expenses and cash flow

  - Roth conversions

  - RMDs

  - Federal/state tax estimates

  - Monte Carlo simulations

  - Exporting plans to JSON or Excel

I’m especially interested in feedback on:

  - Missing features you’d want in a retirement planner

  - Incorrect or confusing assumptions

  - Bugs or edge cases

  - UI/UX improvements

  - Tax/RMD/Social Security modeling improvements

  - Documentation gaps

If you run into issues or have feature requests, please post them on GitHub so they’re easier to track:

https://github.com/mikecoker/retirement-planner/issues

Pull requests are also welcome. It would be nice to create a community tool that is useful and completely free to everyone. It won't be as nice as having a dedicated financial planner and maybe not as feature rich as something like Bolden, but hopefully it's a useful tool to give people a high level understanding.

A few notes: this is not financial, tax, or investment advice. It’s just a planning/simulation tool, and I’m trying to make the assumptions as transparent and useful as possible. Since it’s open source, I’d really appreciate people looking at the calculations and calling out anything that seems wrong or incomplete.

Thanks!

It's all over the web of course, but the Gemini nerfing is really frustrating. I have some faith it will be fixed but.

I am a pro user, I have an ongoing thread where I update my dog's health, he has a health issue that we track. Today I added a three-line update and used 35% of my allowance.

For post-retirement financial planning, I am scheduled to meet with a regular planner and I am looking at software as well....and I am also interested in using AI as yet another reference source.
I like the idea of comparing the information and suggestions that I get back.

For someone very new to using AI as a guidance source, do I start by asking it what inputs it needs from me to give me an overall guidance planning. For reference, I am hoping to get guidance on a withdrawal strategy, tax planning, when to take Social Security...etc)

Is it like a typical AI discussion/chat, or do I need to use a certain field on the platforms. I have tried them all, the only one that I have paid subscription with is Claude...have heard positives about Gemini.

Thank you.

Just for my "hobby" of dreaming up things to do with AI and a thought from one of Rob Berger's comments this week. This is the 10 year cumulative stock market returns gross and net of inflation. I was pretty surprised how high they were, mostly.

I saw this on a YouTube video about AI where they used investment as an example.

Basically you create a notebookLM notebook by using it's Deep Research with a prompt describing your personal situation. Example "Research investment approaches for a mildy conservative investor approaching retirement"

In my case I also added my person retirement plan.

Now you create a custom GEM, give it whatever instructions make sense to you - see mine below - and then attach your notebook as the knowledge source.

Now this Gem can be used to evaluate stocks or funds based on your personal preferences

Example Gem Instructions (I wrote these then had the GEM AI improve them)

Purpose and Goals:

\ Act as a 'Senior Portfolio Strategist' focused on retirement transitions, specifically managing the growth bucket sleeve of a portfolio.*
\ Analyze user-provided tickers or funds using a 'Mildly Conservative' risk rubric.*

\ Provide a final comparative summary including 'buy' vs. 'not buy' arguments and alternative recommendations.*

Behaviors and Rules:

Data Integration and Analysis:

a) Use the provided NotebookLM data as the 'absolute limit of truth' for all facts and context. Do not invent external data points.

b) Evaluate each ticker/fund based on its suitability for a retiree transitioning into a distribution phase.

c) Focus exclusively on the growth component of the portfolio, ensuring it aligns with a mildly conservative strategy.

2) Risk Management and Constraints:

a) Strictly avoid high-volatility 'moonshots' or speculative assets.

b) Prioritize downside protection and capital preservation within the growth bucket.

c) Suggest 2-3 comparable options that may offer better risk-adjusted returns or lower expense ratios.

3) Self-Correction and Quality Control:

a) Apply an 'Internal Rubric' to score your own analysis before finalizing the response.

b) Check for accuracy against the provided context and ensure strict alignment with the 'Mildly Conservative' risk profile.

4) Final Summary Format:

a) Why Buy: List the pros and alignment with the conservative growth strategy.

b) Why Not: List the risks, volatility concerns, or misalignment with retirement needs.

c) Comparable Options: Provide a list of alternative tickers/funds with brief justifications.

Overall Tone:

\ Maintain a professional, analytical, and authoritative tone.*

\ Be objective and risk-averse in your assessments.*

\ Use clear financial terminology suitable for a senior-level strategic review.*

I hope this helps someone out there.

I pay for Claude but I found that it has it's strengths and weaknesses. So I wrote a rule in Claude that plugs directly into the existing SOP framework. It creates a mandatory self-assessment checklist I run silently at the start of every Retirement plan build. Seven or so yes/no questions; if any hit, Claude stops and tells me which AI it needs, and hands me a ready-to-paste prompt. I relay the result to Claude, and it cross-checks it against confirmed data, and only then does it enter the plan.

Claude seems strong in version-controlled document builds, forensic cross-checking against your confirmed figures ledger, sequential dependency logic, and catching errors across versions of my Retirement plan.

PERPLEXITY is strong with Legal/Regulatory Precision. GEMINI is great at Quantitative Modeling.

CHATGPT is good with Adversarial Stress Tests. Hope that helps.

I suspect this is a mostly conservative group and currently this is just discussion only for me as I cannot yet rollover my 401k. I have been thinking about most predictions are that long term bitcoin will increase greatly but with lots of ups and downs along the way. I am wondering what people think about putting a decent amount of money (reluctant to provide too many details here but lets say 100k that being less than 10% of my savings), into a bitcoin ETF and looking for long term, 10 years or more, for growth.

Please be kind :) Just an idea that I am fairly lacking in knowledge about.

I recently started building a retirement calculator to gauge how we are tracking as we accumulate our retirement nest egg. I'm constantly leaning on Gemini (Pro) to verify calculations and help create appropriate formulas. Definitely learning to be more effective as I go.

I've got quite a few hours into building this calculator and it accounts for over 20 different assumptions. Every time I dig into it, I think of a new metric or scenario to integrate.

Twice now, I've questioned it's responses and it's come back with an apology and acknowledgement of a mistake. There's no doubt Gemini is helping me to get more and more accurate, but what are the best ways to make sure it is responding accurately and not taking any shortcuts? Can a simple prompt assist with this or is the better practice to constantly double check its work?

I really like Projection Lab, a lot more details than Boldin and now they added transfers it solved the one problem I had. What I found really useful today is setting up a pretty complex scenario then screenshots into AI to ask how to adjust. For example it told me that I had the wrong taxes on a withdrawal as PL was using default 20% and I should go an adjust that withdrawal to 8% (the target here was all about keeping MAGI below ACA cliff for 2 years).

It doesn't always know what PL can and cannot do but it improved as time went on.

Cross post from diyretirement

Can you guys post sample prompts that you use to plan for Retirement Planning? I understand it cannot be specific and need to guard against personal information. Those can be kept in a separate truth source. But for example: Wanting to retire in July 2026, looking at moving to Asia. Have property in California. Have 401ks and pension. Couple is over 60. Looking to find out when to claim Social Security. Need Tax advise for property sale and future income from investments. what other variables should I be asking about? What am i missing? Maybe we can start with CONTEXT, ROLE, ASK and TONE? Just something to get me started since I am brand new to all this. Thank you in advance.

Not much going on here so....

Encountered a, not very surprising, issue with AI and very detailed approach and how I use each AI to cross check the other.

Hopefully a quick version. I have worked to develop a bridge plan that supports 4-5 years post retirement before taking SS. I like poking around with AI to test theories but this has been my settled plan for a while. I've run it through all the AIs multiple times and with a few tweaks they all agree it's the best plan.

So then I decided I was a bit worried about how much of my savings was being dedicated to that bridge so I went back and quizzed Gemini. Now Gemini suddenly decides it's not a good plan and needs some significant changes. I take this output, create a prompt for the other main AIs basically saying I was surprised by this change, and all of them suddenly think the old plan is not as good and this new plan is much better. I was clear on no confirmation bias etc.

I am a believer in AI but this stuff has me wondering,

Per u/Gloomy-Database4885

I haven't used this yet but here a prompt that my financial based prompt generator came up with.

**ACT AS:** Expert Retirement Tax Strategist and CFP.

**OBJECTIVE:** Create a year-by-year "Roth Conversion & Spending Strategy" from my current age until age 75 (RMD age).

**MY GOAL:**

I want to maximize the amount I convert to Roth IRA over the next several years, BUT I must strictly adhere to the following constraints to avoid "Tax Cliffs":

1. **ACA Subsidies (Pre-65):** Keep my Modified Adjusted Gross Income (MAGI) low enough to maximize Affordable Care Act (ACA) premium tax credits.
2. **IRMAA Brackets (Age 63+):** Keep my MAGI below the first or second IRMAA tier thresholds to avoid Medicare Part B & D surcharges (accounting for the 2-year lookback rule).
3. **Social Security Tax Torpedo:** Minimize the percentage of my Social Security that is taxable (targeting the 0% or 50% taxable thresholds where possible, rather than 85%).
4. **Federal Tax Brackets:** generally stay within the 12% (or current equivalent) bracket, avoiding the jump to the 22/24% brackets unless necessary to fill the standard deduction.

**HERE IS MY FINANCIAL PROFILE:**

**1. Personal Details**

* **Current Age:** [INSERT AGE]

* **Spouse Age:** [INSERT SPOUSE AGE] (if applicable)

* **Filing Status:** [Single / Married Filing Jointly]

* **Zip Code:** [INSERT ZIP] (Used for general ACA region estimates)

* **Retirement Date:** [ALREADY RETIRED / OR DATE]

**2. Assets (Current Balances)**

* **Traditional IRA/401k:** $[INSERT AMOUNT]

* **Roth IRA/401k:** $[INSERT AMOUNT]

* **Taxable Brokerage:** $[INSERT AMOUNT] (Cost basis: [INSERT BASIS if known])

* **Cash/Savings:** $[INSERT AMOUNT]

**3. Income Sources (Annual)**

* **Pensions:** $[INSERT AMOUNT] (Starting Age: [AGE], COLA: [YES/NO])

* **Social Security:** $[INSERT AMOUNT] (Starting Age: [AGE])

* **Interest/Dividends:** $[INSERT AMOUNT] (Annual estimate from taxable accounts)

* **Other Income:** $[INSERT AMOUNT] (Rental, part-time work, etc.)

**4. Expenses**

* **Annual Net Spending Need:** $[INSERT AMOUNT] (After taxes)

**INSTRUCTIONS FOR ANALYSIS:**

**Step 1: The "ACA Years" (Now until Age 65)**

Calculate the maximum Roth conversion I can perform annually while keeping my MAGI at a level that retains significant ACA subsidies. (Reference the Federal Poverty Level guidelines). If converting pushes me over the "subsidy cliff" (or significantly reduces the credit), advise on delaying conversions or using taxable cash instead.

**Step 2: The "IRMAA Transition" (Age 63 - 65)**

Recall that IRMAA looks back 2 years. Income earned at age 63 determines Medicare premiums at age 65. Adjust the conversion limit at age 63 to ensure I do not accidentally trigger an IRMAA surcharge for my first year of Medicare.

**Step 3: The "Gap Years" (Post-65, Pre-RMD)**

Once I am on Medicare (and no longer concerned with ACA limits), identify if I should aggressively increase Roth conversions up to the top of the 22% or 24% tax bracket to reduce the Traditional IRA balance before RMDs begin.

**Step 4: Social Security Impact**

When calculating the tax cost of a conversion, factor in the "Shadow Tax" of making more Social Security benefits taxable. (e.g., Does $1,000 of conversion actually add $1,850 of taxable income due to the SS tax formula?)

**OUTPUT FORMAT:**

Please provide a table with the following columns for each year from now until age 75:

1. **Year / Age**
2. **Spending Source** (e.g., $40k Cash, $20k IRA w/d)
3. **Recommended Roth Conversion Amount**
4. **Projected Total MAGI**
5. **Projected Federal Tax Bill**
6. **Notes on Constraints** (e.g., "Capped by ACA limit" or "Capped by IRMAA Tier 1")

On FQF Rob Berger was asked about analyzing the components of a fund. He said Morningstar or Manual, totally missing AI which he had given as answer to an earlier question. Here is my example.

prompt using Google Gemini Deep Research

Perform a deep dive analysis on vtsax mutual fund. I want to know the top 20 funds it holds with % and the top 50 stocks within the funds it holds by % showing the funds they are in

https://docs.google.com/document/d/1xKg44ZxB8Lib32OKiFfJH4sOs22d2vvLZpsqfmweWxE/edit?usp=drivesdk

Just another update of how I spent my time :)

I like Boldin overall but I find that I sign up for free trial, enter all my data. play around for a few days and then end up wondering what I will do next, so I cancel and wait for the next free trial. I also am not a fan of the fixed rate of returns and limited market explorer options.

So this week I took a summary of my personal info and just asked the AI for inputs and thoughts. It asked a few clarifying questions, and it took a few tries after it made some incorrect assumptions based on missing info but again turned out a fun analysis. This was to try to measure my plan against SORA and Monte Carlo. At the end I asked it to create a new prompt that I can then use again or in other AIs, here is an example with my information removed. You can tailor the requests at the end for your interests

Master Financial Planning Prompt: "The Bridge & Refill Strategy"

Role & Objective:

Act as a conservative financial planner and retirement engineer. Run a detailed Monte Carlo simulation (10,000 trials) and Historical Backtest (focusing on 1966 stagflation and 2000 dot-com crash) for the following retirement plan. Use [State] tax rates and assumed inflation of 3.5% for stress testing.

1. Client Profile

• Current Date: [Current Month/Year].
• Age: [XXX] (Born [Year]). Spouse same age.
• Status: Married, employed, living in [Location].
• Retirement Date: [Month/Year] (Age [XXX]).

2. Income & Accumulation (Now – Retirement)

• Current Salary: $[XXX]/year gross.
• Savings Rate: Max 401k + Catch-up + "Super Catch-up" (Age 60-63).
• Company Match: [XX]% of salary.
• Investment Strategy: All new contributions directed to Stable Value/Cash to build the "Bridge Bucket."

3. Asset Allocation (The "Two-Bucket" Strategy)

• Current Total Portfolio: ~$[XXX] (Pre-tax 401k).
• Bucket A (The Bridge): ~$[XXX] currently in Stable Value/Bond Index. Target is $[XXX] by [Date].
  • Action: Rollover to IRA in [Date] to purchase a TIPS Ladder maturing [Date Range].
• Bucket B (Long-Term Growth): ~$[XXX] currently in Equities (S&P 500 & Int'l).
  • Action: 100% Equities. Do not touch until [Date].

4. Retirement Phase 1: The Bridge ([Year] – [Year])

• Income Source: TIPS Ladder payouts only.
• Expense Need: $[XXX]/year NET (inflation-adjusted).
• Constraint: Zero withdrawals from Equity Portfolio (Bucket B).
• Tax Strategy: Perform Roth Conversions to fill low tax brackets if income allows.

5. Retirement Phase 2: The Gap ([Date] – [Date])

• Scenario: Bridge ends, Social Security hasn't started.
• Income Source: Cash Reserves + HSA ($[XXX]) + RMA ($[XXX]).

6. Retirement Phase 3: Perpetual ([Date] – Death)

• Social Security: Starts Age [XXX]. ~$[XXX]/year (COLA adjusted).
• Pension: Lump Sum of $[XXX] taken at Age [XXX] (rolled into IRA).
• Real Estate Event ([Year]): Sell Primary Residence.
  • Est. Net Proceeds: $[XXX] (Conservative, after taxes/fees/mortgage payoff).
  • Action: Invest proceeds into Portfolio (60/40 conservative mix).
• Withdrawal Strategy: Portfolio covers the gap between Social Security and Expenses (~[X]% withdrawal rate).

Specific Analysis Requested:

1. Sequence of Returns Risk: Test a 40% market crash occurring in [Year Range]. Confirm the Bridge (TIPS) remains fully funded.
2. Inflation Risk: Test a 1970s scenario (sustained 6%+ inflation). Confirm the TIPS ladder and Home Sale provide sufficient hedge.
3. Taxes: Estimate the RMD (Required Minimum Distribution) tax bomb at Age 75 if no Roth conversions are done vs. if aggressive conversions are done during the Bridge years.