What counts as a 'day abroad' for the 330-day rule?

A full calendar day where you are physically present in foreign country/countries at midnight UTC. Travel days are tricky: the day you leave the US doesn't count if you arrive in the foreign country before midnight; partial days in the US (layovers, stopovers, technical stops) are days NOT abroad. Cruise days in international waters are not abroad — only foreign country days. The 12-month period is consecutive, not aligned to tax year — you can pick any 12-month window that gives you 330 days.

What's the difference between Physical Presence Test and Bona Fide Residence Test?

Physical Presence is the count-the-days mechanical test (330+ days in a 12-month period). Bona Fide Residence is a fact-and-circumstances test that requires you've established residence in a foreign country for an entire tax year — local bank accounts, work visa or residence permit, family relocated, integration into the local community. Bona Fide is more flexible (can travel back to US for visits without resetting the clock) but requires more rooting evidence. Most digital nomads use Physical Presence; expats with permanent positions use Bona Fide.

What if I'm 11 days short of 330 — can I extend my trip?

If you're approaching the 12-month deadline and still short, yes. The Physical Presence period can extend beyond the tax year — you can claim FEIE on year 1's income by demonstrating you completed 330 days within a 12-month period that ended in year 2. Form 2555 lets you specify the qualifying period. The downside: you have to file an extension on year 1's return until the period closes. Many expat CPAs handle this routinely.

Does the FEIE benefit transfer to my IRA / Roth contribution limits?

No — and this is a common mistake. FEIE excludes income for federal tax purposes, but the IRS treats FEIE-excluded income as having occurred for IRA contribution eligibility. If your only income is FEIE-excluded, you have no 'compensation' for IRA purposes and can't contribute. Workaround: leave some income un-excluded (use FTC instead of FEIE), or have spouse contribute via IRA spousal contribution. Roth IRA phaseout uses MAGI which DOES include FEIE income — so high earners may be phased out of Roth even with FEIE.

I Was 11 Days Short of FEIE — Here's What That Cost Me

The Trap That Eats Newcomer Nomads

Marcus quit his SF tech job in late 2024 and moved to Lisbon. The plan was straightforward: bootstrap his SaaS, qualify for FEIE, save $30K+ on US taxes per year. He flew out December 15. He ran an early-2025 trip back to the US for 18 days for his sister’s wedding. Then a 12-day client onsite in Austin in October 2025.

When his CPA filed his 2025 return, the math was brutal:

Days	Where
17	December 15-31 in Portugal
348	Jan 1 - Dec 31 in Portugal (calendar 2025)
(-) 18	Sister’s wedding trip
(-) 12	Austin client onsite
319	Net days abroad in 2025

He was 11 days short of 330. FEIE applied to $0 of his $145K income. The full amount became US federally taxable.

The cost: $32,000 in extra federal tax, plus $4,200 in CA state tax (he hadn’t broken CA domicile yet), plus the Portugal NHR rate ~10% on the same income. His total tax bite was $51,000 instead of the $14,000 he’d planned for.

He could have avoided this with one phone call to his CPA before the wedding trip.

The 330-Day Rule Is Binary

The most counterintuitive thing about FEIE is the all-or-nothing structure. There’s no partial credit.

Days abroad	FEIE applies?	Federal tax on $145K
329	NO — 0 days short	~$32,000
330	YES — qualified	~$0 (under cap)
365	YES — qualified	~$0

A single day of difference creates a $32,000 swing. This is unlike most US tax provisions which graduate or phase out — FEIE is a step function.

The Workaround People Don’t Talk About

If you’re approaching the deadline and short on days, the qualifying 12-month window can extend beyond the tax year. Form 2555 lets you specify any 12-month period for the Physical Presence Test.

Practical example: Marcus’s 12-month window for tax year 2025 could be January 15 2025 → January 14 2026. If he stays in Portugal continuously from December 15 2024 through January 14 2026, his window has:

17 days (Dec 2024 to Jan 14 2025) — outside tax year, but inside qualifying window
All of Jan 15 2025 - Dec 31 2025 minus the 30 days back in US (319 days)
Jan 1 - Jan 14 2026 (14 days) — outside tax year, but inside qualifying window

Total: 350 days in the qualifying window. He claims FEIE on his 2025 income by extending the qualifying period into 2026. Form 2555 has a specific line for “Extension to file return until [date]” — many expat CPAs file this routinely.

The cost: he files an extension on the 2025 return (typically due April 15) to October 15 2026, by which point his qualifying period has closed.

Where this scenario doesn’t apply

The framework above assumes a few things. Counter-examples worth flagging:

You stayed in CA after moving abroad. California aggressively claims domicile based on indirect ties (driver’s license, voter registration, primary residence). Even with full FEIE, CA can take 9% effective on worldwide income. The fix is breaking domicile cleanly: full year out, register-to-vote in TX/FL/WA/NV, change driver’s license, sell or convert primary residence to rental.
You have substantial US-source passive income. Dividends, interest, capital gains from US brokerage accounts are NOT foreign-earned income. FEIE doesn’t apply. You’d still owe federal tax on those. Many digital nomads forget this and panic when 1099-DIV arrives.
You exercised ISO options abroad. ISO bargain element is AMT preference income, not foreign-earned income. FEIE doesn’t apply. Pair with the ISO AMT Calculator — you can have FEIE saving you $30K on salary and AMT taking $80K on ISO exercise in the same year.
You’re abroad on a US employer payroll, not foreign payroll. US-source income (W-2 from US employer for services performed abroad) DOES qualify for FEIE on the foreign-services portion. Check your W-2 — your employer should be reporting “foreign-source” wages on Box 18. If they’re not, there’s a compliance issue both for you and the employer.
You’re a US citizen abroad for under 12 months. No FEIE possible. Use FTC only. Often combined with treaty residency claims to reduce double-tax burden.

The Honest Tax Burden Comparison

For a $150K-earner running a real comparison:

Scenario	Total tax	Effective rate
Stayed in CA	$48,000	32%
Stayed in TX/FL	$32,000	21%
Lisbon FEIE-qualified, no CA claim	$14,000	9%
Lisbon FEIE-failed (under 330 days), no CA claim	$42,000	28%
Lisbon FEIE-qualified, CA still claims	$26,500	18%

The difference between “Lisbon nomad doing it right” and “Lisbon nomad missing FEIE” is $28K per year. Almost entirely from one rule.

The difference between “Lisbon nomad” and “Lisbon nomad with CA still claiming” is $12K per year. Worth the cost of breaking domicile cleanly before you go.

What 5-Year Pictures Look Like

We modeled three common digital nomad scenarios at $150K income:

Path	5y total tax	Notes
Stayed in CA	$240,000	The baseline most people compare against
Lisbon, FEIE-qualified, TX domicile	$70,000	The dream scenario
Lisbon, missed FEIE 1 year out of 5	$138,000	1 year of failure costs $30K
Bali, FTC-only, no FEIE	$120,000	Foreign tax low, no FEIE benefit, still beats CA
London, FTC fully crediting FEIE	$180,000	UK tax exceeds US, no benefit from leaving

Where the calculator falls short

No housing exclusion modeling. FEIE has a separate housing exclusion that adds ~$33K-54K depending on city (Singapore high, rural India low). Form 2555 housing component.
No SE tax modeling. Self-employed digital nomads still owe 15.3% SE tax even when FEIE applies. Only Totalization Treaty countries (~25 countries) exempt this.
No state-domicile detection. Whether CA still claims you depends on a fact pattern we can’t capture in a slider. The “high state” toggle is binary; reality is gradient.
No social-security taxation. US Social Security benefits abroad are taxed differently depending on bilateral treaty. Not modeled.
Single year only. Multi-year planning (e.g., bunching foreign tax payments to maximize FTC carryforward) requires more sophisticated modeling.
Federal brackets simplified. We use approximate brackets, not full IRS tables.

What to actually do

Track days obsessively. Use a passport-stamp app or Google Maps timeline. Verify your day count quarterly, not at year-end.
Plan US visits with the math in mind. A wedding in October is recoverable; a wedding in December (close to year-end with no Q1 buffer) is dangerous.
Break state domicile before you go. Sell or rent out CA home. Change driver license. Register to vote elsewhere. Set up a TX/FL bank as primary. Six months before departure is ideal.
Use Form 2555 extension if you’re short. Don’t accept the loss — file an extension and finish the qualifying period in year 2.
Get a CPA quote. Greenback, Bright!Tax, MyExpatTaxes specialize in expat returns. $350-1,500/year is normal. The complexity is worth professional help.
Don’t combine FEIE and ISO exercises. If you have significant ISOs to exercise, plan a tax year where you’re either fully US-resident OR don’t exercise. The interaction creates unexpected AMT.

Open the Digital Nomad Tax Calculator → and run your specific income, days abroad, and state-claim scenario. Pair with the Geo-Arbitrage Calculator for COL-based savings and the ISO AMT Calculator if you have stock options to exercise.