You end with a funded Roth IRA growing tax-free
Picture this: Roth open at a low-cost broker, first contribution (or conversion) settled, beneficiaries named, a plain total-market ETF buying shares. Money you already paid tax on can leave anytime. Earnings leave tax-free once the rules clear. No lifetime RMDs for you as the original owner. That finish line is the whole point of how to open a Roth IRA.
Most people never hit it. Phase-outs feel fuzzy, six broker tabs stay open, and one sloppy backdoor or excess contribution turns into a multi-year excise mess. Happy-path “5 steps” pages do not pressure-test your MAGI or your forgotten rollover IRA.
Those pages fail for a boring reason. They paste a static eligibility table, skip how MAGI is built from the return, wave past pro-rata aggregation, and never hand you a prompt that forces the ugly branches into the open. Robos will rebalance after funding; they will not catch a December 31 IRA total that poisons a conversion. DIY broker flows assume you already speak IRS.
Where AI actually helps (and where it must shut up)
Keep control. A general LLM – ChatGPT, Claude, Gemini, whoever – is a research and checklist engine, not your tax advisor. You paste public IRS figures plus a rough snapshot of your life, take the structured output, then verify on irs.gov before any “open account” click.
DIY at a major broker is free and fast if you already know MAGI math and the two five-year clocks. A robo handles the portfolio after the cash lands and charges a small AUM fee; it still will not save you from pro-rata. AI sits in the messy middle: cheap, good at rewriting dense IRS language into checklists and scorecards, dangerous if you treat the chat as signed advice. I use it for eligibility modeling, provider tables, and Form 8606 reminders – then I execute at the broker.
Work backward: lock the 2026 end-state numbers first
$7,500 combined traditional + Roth if you’re under 50. $8,600 at 50+ (that $1,100 catch-up). Not more than your taxable compensation. Roth dollars are not deductible on the way in; qualified earnings come out tax-free. That is the 2026 box, per the IRS announcement (IR-2025-111 / Notice 2025-67).
MAGI gates for 2026 hit hard at round numbers. Single or head of household: full contribution below $153,000, phase-out $153k-$168k, nothing at $168,000+. Married filing jointly: full below $242,000, phase-out to $252,000, none above. Married filing separately and lived with your spouse: a thin $0-$10,000 window. Cross-check the dollars on the IRS 2026 limits newsroom page – do not trust a chatbot’s memory of last year’s band.
Paste this and fill the brackets:
Act as a careful research assistant, not an advisor. Using only 2026 IRS Roth IRA rules:
- Contribution limit under/over 50
- MAGI phase-outs by filing status
My approx situation: [age], [filing status], estimated MAGI $[X], earned income $[Y].
1. Can I contribute directly? Full, partial, or none?
2. If partial, rough formula for the reduced amount.
3. List exact documents I'll need to open at a broker.
4. Flag any backdoor or excess-contribution risks.
Cite the public IRS figures you used. Remind me to verify on irs.gov.
You should get phase-out math plus a doc list: SSN/ITIN, government ID, employment/income info, bank routing, beneficiaries. Official overview of who can contribute (earned income, no max age, account must be designated Roth at setup) lives on the IRS Roth IRAs page. Near a cutoff? Wait for a cleaner MAGI read – or send a deliberately small partial.
Choose the account home and open it
Custodian next. Ask the model for a side-by-side on fees, minimums, fund/ETF choice, and IRA tools across three places you already tolerate. Most big online brokers still advertise $0 account minimums; the identity + funding flow is often done in roughly 10-15 minutes.
| Factor | Self-directed broker | Robo-advisor |
|---|---|---|
| Control | You pick every ETF/fund | Algorithm builds & rebalances |
| Typical cost | $0 account fee + fund expense ratios | Small AUM fee + funds |
| Best if | Total-market index and leave it | You want set-and-forget after funding |
| AI role | Compare expense ratios & IRA screens | Still run eligibility before you sign |
Docs in hand. Provider’s retirement/IRA page → Roth IRA → identity and bank link. Name primary and contingent beneficiaries in the same sitting – people ghost that field and only notice when estate paperwork gets ugly. Account status shows open? Push the ACH. Current-year money anytime; prior-year money until the tax-return due date (usually mid-April), not December 31 – see the IRS traditional & Roth IRA timing rules.
Backdoor path? Before a single dollar moves, have the model outline Form 8606 and the pro-rata rule. The IRS aggregates every traditional, SEP, and SIMPLE IRA you hold on December 31 – not just the new nondeductible contribution. One forgotten rollover can make most of the conversion taxable.
Real-world walk-through with the AI checklist
Sam, 34, single, MAGI about $140k, W-2 well above the contribution cap. He runs the eligibility prompt. Model says full $7,500 direct is fine and spits the doc list. Second prompt: compare three low-cost brokers on account fees, fractional shares, and contribution tracking for a DIY index buyer. He opens on his phone, ACHs $7,500, buys a total U.S. market ETF the same day. Active work: under an hour across one evening.
Same Sam at $160k MAGI? The prompt flags partial contribution, sketches the reduced-limit math, and surfaces backdoor + pro-rata in the same breath. Linear tutorials skip that branch.
Broker choice anxiety is mostly theater once fees and index access are similar. The expensive mistakes are compliance clocks – not whether your app icon is red or blue.
Two clocks and the 6% trap
Cash is in. Now the timers. Account-level five-year clock for earnings to be qualified: starts January 1 of the tax year of your first-ever Roth contribution. Prior-year contribution made by the April deadline can back-date that clock to January 1 of the prior year – almost a full year shaved off, and most open-an-account pages never say it out loud. Each conversion carries its own five-year clock; pull the taxable converted amount too early while under 59½ and you can owe the 10% penalty on top of tax you already paid at conversion. Contributions themselves? Available tax- and penalty-free. Qualified distribution rules and the conversion recapture logic are laid out in IRS Publication 590-B.
The catch is excess. Over the annual limit – or a direct Roth when MAGI says no – and a 6% excise tax hits every year the excess stays. Remove excess plus earnings by the filing deadline, or recharacterize. The model can draft a “I already overfunded” tree; you still fix it with the custodian and, if the numbers are ugly, a tax pro. Base rules sit in Pub 590-A / the IRS contribution-limits topics.
FAQ
Can I open a Roth IRA if I already have a 401(k)?
Yes. Separate buckets. IRA limit does not care what you deferred at work – only the combined traditional + Roth IRA cap.
What if my income is too high for a direct contribution?
Open the Roth anyway. High earners use the backdoor: nondeductible traditional contribution, then convert (Form 8606). No income cap on the conversion itself. Remember the pro-rata warning above – if pre-tax IRA balances are large, some plans let you roll those into a current 401(k) first to clean the slate. Run rough numbers in chat; confirm with a tax professional before you move real money.
Does opening cost anything, and how fast does funding clear?
Major brokers: usually $0 to open or keep a basic Roth. ACH often lands in a few business days; some firms grant partial buying power sooner. Invest when cash shows settled. Recurring contribution if you want the habit. Long-term “fee” that matters is the expense ratio inside the account.
Open the chat. Paste the eligibility prompt with real numbers. Verify the IRS figures. Finish the broker application before the tab goes cold.