---
name: preparing-us-personal-tax-returns
description: Helps organize and prepare a US federal individual income tax return (Form 1040) — document checklist, filing status, standard vs itemized decision, schedule mapping, credits, deadlines, and estimated-tax safe harbors. Use when the user asks for help preparing, organizing, or checking their US personal tax return, 1040, W-2/1099 documents, IRS filing deadlines, refund estimation, or which schedules and credits apply. Do not use for Canadian returns (preparing-canadian-personal-tax-returns), business entity returns (filing-us-business-taxes), or tax planning strategy (optimizing-us-personal-taxes).
---

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Author: Simon-Pierre Boucher
Contact: contact@spboucher.ai
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# Preparing US Personal Tax Returns

## When to use / when NOT to use
- **Use for:** organizing documents, mapping income and deductions to Form 1040 and its schedules, choosing filing status, standard-vs-itemized comparison, credit eligibility screening, deadline and payment questions for an individual federal return.
- **Do NOT use for:** Canadian T1 returns, business entity returns (1120/1120-S/1065), state returns (mention that a state return likely also applies, then stop), or planning strategy for future years.

## Important limits
- Educational preparation help, not professional tax advice — complex situations (multi-state, equity compensation, trusts, audits) go to a CPA or EA.
- All figures below are stated for **tax year 2026** and MUST be verified against [irs.gov](https://www.irs.gov) before use.
- Never assist with evasion — unreported income or fabricated deductions are out of scope; if asked, decline and explain the legal alternative.

## Workflow
1. Collect documents against the checklist: W-2s (every employer), 1099s (NEC, MISC, INT, DIV, B, R, K, G, SSA), 1098 (mortgage) / 1098-T (tuition) / 1098-E (student loan), HSA forms (1099-SA, 5498-SA), prior-year return, IP PIN if issued.
2. Determine filing status (Single, MFJ, MFS, Head of Household, Qualifying Surviving Spouse) — marital status on December 31 controls; HoH requires an unmarried filer paying >half the cost of a home for a qualifying person.
3. Map each income item to its schedule (see the schedule map in [references/reference.md](references/reference.md)).
4. Compare standard deduction vs itemized (Schedule A: SALT, mortgage interest, medical above the AGI floor, donations). Pick the larger; note MFS must both itemize or both take standard.
5. Screen credits: Child Tax Credit, EITC, education credits (AOTC/LLC), child & dependent care, Saver's Credit — check phase-outs in the reference file.
6. Compute balance due or refund; if balance due is large, check the estimated-tax safe harbor for next year (90% of current-year tax, or 100% of prior-year tax — 110% if prior-year AGI exceeded $150,000).
7. **Validate:** every document from step 1 appears on the return; totals on the return match source-document totals; filing status is consistent across the return; flag any 1099 income with no matching entry.

## Current figures (tax year 2026 — verify before use)
| Item | Value | Source |
|---|---|---|
| Brackets | 10 / 12 / 22 / 24 / 32 / 35 / 37% | irs.gov |
| Standard deduction | $16,100 single · $32,200 MFJ | irs.gov |
| Filing deadline | April 15, 2027 (TY2026) | irs.gov |
| Extension (Form 4868) | To Oct 15 — extends filing, NOT payment | irs.gov |
| Estimated-tax safe harbor | 90% current / 100% prior (110% if AGI > $150k) | irs.gov |
| 401(k) elective deferral | $24,500 (+$8,000 catch-up 50+) | irs.gov |
| IRA limit | $7,500 (+$1,100 catch-up) | irs.gov |
| HSA limit | $4,400 self / $8,750 family | irs.gov |

## Edge cases & failure modes
- **Missing W-2/1099** → request a wage and income transcript from the IRS; never estimate silently.
- **Error found after filing** → amend with Form 1040-X; do not re-file a second original.
- **First-time filer** → no prior-year AGI for e-file identity check; use $0.
- **Can't pay** → file anyway: the failure-to-file penalty (5%/month) is 10× the failure-to-pay penalty (0.5%/month); set up an IRS payment plan.
- **Marketplace health coverage (1095-A)** → Form 8962 is mandatory; the return will reject without it.

## References
Full schedule map, credit phase-out table, deadline calendar, penalty structure, and worked examples: see [references/reference.md](references/reference.md).