▲ Cairn
The early-retirement planner for the years before 59½.
Most retirement software assumes you work to 65 and flip on Social Security and Medicare the same year. Cairn is built for the people who leave early — and models the hard part every generic calculator skips: bridging the gap years before your retirement accounts unlock, penalty-free.
Download free (Windows)How it works
Also on macOS and Linux. Runs on your own computer — nothing is uploaded, no account, no cloud. Your finances never leave your machine.
What it does
The bridge years, mapped
Rule of 55, 72(t)/SEPP, the Roth-conversion ladder, the 457(b) exception, and the ACA subsidy cliff before 65 — modeled explicitly, year by year, with a separate “is the money accessible, not just sufficient” check.
Two honest stress tests
Monte Carlo shown beside a real 1928–2025 historical backtest — whether they agree, or diverge, is the honest signal about sequence-of-returns risk, not one fake-precise number.
Tax strategy that pays off later
Roth-conversion “bracket fill” weighed against the ACA cliff, plus an RMD tax-bomb warning and the low-income window to defuse it — the moves that quietly cut lifetime tax.
Real households, two incomes
Per-person retirement ages, pension COLA and survivor elections, Social Security claiming coordination, and each account growing at a return that matches how it’s actually invested.
Runs on your computer
Cairn is a local app. Your income, balances, and plans stay on your machine and never touch a server — a straight answer for anyone who’d rather not hand their finances to a website.
Sourced and audited
Every dated tax and benefit figure traces to a primary IRS or CMS source, and the engine has been through a documented citation-and-logic audit. It’s decision support you can question — not answers from a black box.
Download Cairn
Free for individuals, on Windows, macOS, and Linux. Grab the latest build for your platform and run it — there’s no sign-up, no upload, and no cloud. The first run walks you through a household so you’re never staring at a blank screen.
WindowsmacOSLinuxView the source
Every number sourced to the IRS / CMS · open, auditable engine · software, not advice. The sources and the citation-and-logic audit are on GitHub.
How it works
- You enter your householdAges and retirement targets, incomes and account balances and how each is invested, pensions, Social Security, and a spending target. Your numbers stay on your machine.
- The model runs — not a conversationA deterministic engine projects your plan in real dollars, checks whether the money you can actually reach covers the bridge years, and runs both the Monte Carlo and the historical backtest — the same inputs always give the same answer.
- You get an honest picture, and a plan of recordFeasibility odds, the earliest age you can realistically retire, the year-by-year access path, and an optimized conversion schedule — each with the reasoning spelled out, and printable as a one-page plan.
For financial advisors
A defensible bridge-years tool for your practice
Cairn is built for the clients most retirement software ignores — the ones who don’t work to 65. There’s a commercial, white-label license for fee-only advisors who want it as a client-facing deliverable.
The bridge years, done right
Rule of 55, 72(t)/SEPP, the Roth ladder, the 457(b) exception, and the ACA cliff before 65 — modeled per year, with a separate check on whether the money is accessible, not just sufficient.
Defensible, not a black box
Every dated tax and benefit figure traces to a primary IRS/CMS source, and the engine has been through a documented citation-and-logic audit — decision support you interpret with the client.
Client data stays put
Cairn runs locally on your machine. Client financials never touch a vendor’s server — a straight answer for privacy-conscious clients and a simpler compliance story for you.
A deliverable, white-labeled
Generate a one-page plan of record — the bottom line, the money picture, the year-by-year path, and prioritized next steps — with your firm’s name on it, to hand the client.
Join the design-partner cohort
We’re onboarding a small first group of fee-only advisors — free for the first year — to get Cairn right for real practices. You get direct input on the roadmap and priority support; we get your honest read on fit and pricing. A 15-minute walkthrough is the whole ask.
Book a 15-min walkthroughor email licensing@trueascentlabs.com
Software, not advice
Cairn is planning and educational software — not financial, tax, or legal advice, and not a recommendation to buy or sell anything. Using it does not make True Ascent Labs LLC your adviser. Projections are estimates based on your inputs and modeling assumptions, not guarantees. Verify any irreversible decision with a licensed fee-only fiduciary advisor and a CPA.