An open-source, drop-in replacement for TAXSIM35. Same interface, same inputs, same outputs — powered by PolicyEngine's microsimulation engine.
# Install uv package manager (if you don't have it)
curl -LsSf https://astral.sh/uv/install.sh | sh
# Install policyengine-taxsim
uv tool install policyengine-taxsimSame input format, same output variables. Just swap the command.
taxsim35 < input.csv > output.csvpolicyengine-taxsim < input.csv > output.csvOr run it directly in your browser.
Try it onlinePolicyEngine and TAXSIM have been cross-validated against each other since 2021, comparing results across thousands of CPS households. That work led to a formal partnership with NBER.
All code — the TAXSIM emulator and the PolicyEngine engine it runs on — is open source on GitHub. Inspect every calculation.
Same stdin/stdout interface, same input variables, same output format. Just swap taxsim35 for policyengine-taxsim.
Automatic year-stitching routes 2021+ to PolicyEngine and earlier years to TAXSIM35, covering the 1960s through future scheduled law changes in a single command.
Built under a memorandum of understanding with the National Bureau of Economic Research and TAXSIM creator Daniel Feenberg.
Read moreThree-way validation with the Atlanta Fed's Policy Rules Database — cross-checking PolicyEngine, TAXSIM, and the Fed's models.
Read moreTAXSIM covers federal and state income taxes. PolicyEngine goes further — benefit programs, payroll taxes, detailed credits, and full microsimulation on representative survey data.
Estimate the budgetary and distributional impact of policy reforms across the full US population using PolicyEngine's Enhanced CPS, which integrates and calibrates multiple survey datasets.
SNAP, SSI, Medicaid, CHIP, ACA marketplace subsidies, TANF, housing vouchers, WIC, EITC, CTC, and hundreds more federal and state programs — all in one model.