---
name: us-states-references
description: Primary source references and related open-source projects for this jurisdiction.
license: AGPL-3.0-or-later (code) / OpenAccountants Guide License v1.0 (content)
metadata:
  source: openaccountants
  jurisdiction: US
  category: tax
  quality: source-cited draft
  openaccountants_url: "https://openaccountants.com/skills/us-states-references"
  obligation: OTHER
---

# United States — Related Open-Source Projects

> **General reference only.** This skill is general tax/accounting reference material for AI-assisted workflows. It has not been reviewed for any specific person's facts, documents, elections, deadlines, residency, filing status, or local procedures. Do not rely on it to file, pay, amend, or take a tax position without review by a qualified professional in the relevant jurisdiction.

OpenAccountants is AGPL-3.0. All projects below have compatible licenses. Projects below can be incorporated with attribution.

## policyengine-us

- Repository: [PolicyEngine/policyengine-us](https://github.com/PolicyEngine/policyengine-us)
- License: AGPL-3.0
- Stars: 145
- Language: Python
- Scope: The definitive US tax-benefit microsimulation model. Covers federal income tax, EITC, CTC, SNAP, Medicaid, SSI, state income taxes for all 50 states, and more.
- Integration: Same AGPL-3.0 license — fully compatible. Federal and state tax computation logic can be directly incorporated.

## py1040

- Repository: [b-k/py1040](https://github.com/b-k/py1040)
- License: GPL-2.0
- Stars: 338
- Language: Python
- Scope: US personal income tax calculator implementing Form 1040. Covers standard/itemized deductions, tax brackets, credits.
- Integration: GPL-2.0 is compatible with AGPL-3.0 (downstream must remain AGPL-3.0). Form 1040 logic and bracket calculations can be adapted.

## Tax-Calculator

- Repository: [PSLmodels/Tax-Calculator](https://github.com/PSLmodels/Tax-Calculator)
- License: Custom open-source
- Stars: 297
- Language: Python
- Scope: USA Federal Individual Income and Payroll Tax Microsimulation Model. Academic-grade tax policy analysis tool.
- Integration: Custom open-source license — verify specific terms before incorporating. Useful as a reference for federal tax policy modeling and validation.

---

_Source: [OpenAccountants](https://openaccountants.com/skills/us-states-references) — open tax Guides for AI, reviewed by named CPAs/CAs/EAs. Quality: **source-cited draft**. For always-current figures and named-accountant backing, connect the OpenAccountants MCP server (`openaccountants-mcp`)._