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Tax

Federal income tax, capital gains, and after-tax projections.


calculate_federal_income_tax

Calculate federal income tax for the given taxable income and filing status.

Parameter Type Default Description
taxable_income_cents int required Taxable income in cents
filing_status string required Tax filing status. Options: single, married_joint, married_separate, or head_of_household
tax_year int 2025 Tax year (2024 or 2025)

Returns tax owed, effective rate, and marginal rate.


calculate_capital_gains_tax_rate

Get the long-term capital gains tax rate based on income and filing status.

Parameter Type Default Description
taxable_income_cents int required Taxable income in cents (before capital gains)
filing_status string required Tax filing status. Options: single, married_joint, married_separate, or head_of_household
tax_year int 2025 Tax year (2024 or 2025)

Returns the LTCG rate (0%, 15%, or 20%) that applies to the given income level.


apply_after_tax_to_projection_result

Apply withdrawal taxes to a projection result, computing after-tax spendable values.

Parameter Type Default Description
projection_result_json object required The 'projection_result' object from run_projection's output. Pass the value of the 'projection_result' key directly.
account_tax_treatment string required Account tax treatment category. pre_tax: Traditional 401k/IRA (withdrawals taxed as ordinary income). post_tax_deferred: Roth 401k/IRA (tax-free withdrawals). taxable: Brokerage or savings (capital gains on liquidation). tax_advantaged: HSA, 529 (tax-free for qualified expenses).
marginal_ordinary_rate float required Marginal ordinary income tax rate as decimal (e.g., 0.22 = 22%).
ltcg_rate float required Long-term capital gains tax rate as decimal (e.g., 0.15 = 15%).
taxable_income_type string "none" How income from this account is taxed on withdrawal. none: Tax-deferred accounts (Traditional IRA, Roth). ordinary_income: Cash accounts (savings, checking). investment_income: Brokerage accounts (capital gains on sale).
initial_cost_basis_cents int null For taxable brokerage accounts: the original invested amount in cents. Cost basis stays fixed as the portfolio grows, so the taxable gain fraction increases over time. Ignored for non-brokerage accounts.

Returns the adjusted projection result with corrected after_tax_percentiles.