joellewis/tax-efficiency

Tax-Efficient Investing

Purpose

Maximize after-tax returns through strategic asset location, tax-loss harvesting, gain/loss management, and withdrawal sequencing. This skill addresses both the accumulation phase (minimizing tax drag) and the distribution phase (optimizing withdrawal order across account types).

Layer

5 — Policy & Planning

Direction

both

When to Use

• Deciding which assets to hold in taxable vs tax-deferred vs tax-exempt (Roth) accounts
• Evaluating tax-loss harvesting opportunities and managing wash-sale compliance
• Computing after-tax returns and tax drag on portfolio performance
• Planning Roth conversion strategies and breakeven analysis
• Designing tax-efficient withdrawal sequences in retirement
• Evaluating charitable giving strategies with appreciated securities
• Managing tax lot selection to minimize realized gains
• Planning around Required Minimum Distributions (RMDs)

Core Concepts

Asset Location

Place tax-inefficient assets in tax-advantaged accounts and tax-efficient assets in taxable accounts:

• Tax-deferred accounts (Traditional IRA, 401k): Bonds, REITs, high-turnover funds, TIPS — assets generating ordinary income
• Tax-exempt accounts (Roth IRA, Roth 401k): Highest expected growth assets — all growth is permanently tax-free
• Taxable accounts: Index equity funds (low turnover, qualified dividends, tax-loss harvesting eligible), municipal bonds, tax-managed funds

The benefit of asset location increases with the spread between ordinary income tax rates and capital gains rates, and with the size of the tax-advantaged accounts relative to total portfolio.

Tax-Loss Harvesting (TLH)

Realize investment losses to offset capital gains, reducing current tax liability while maintaining market exposure:

• Sell a losing position, immediately buy a similar (but not "substantially identical") replacement
• Harvested losses offset gains dollar-for-dollar; net losses offset up to $3,000 of ordinary income per year; excess carries forward indefinitely
• Wash-sale rule (30 days): Cannot repurchase the same or substantially identical security within 30 days before or after the sale — applies across all accounts (including spouse's accounts and IRAs)
• Tax alpha from TLH: Estimated 0.5-1.5% per year in early years of a portfolio's life, declining as cost basis rises
• Best opportunities arise during market volatility and in the first few years of investing

After-Tax Return

Different income types face different tax rates:

• Interest income: Taxed at ordinary income rates
• Qualified dividends: Taxed at long-term capital gains rates (0%, 15%, or 20% + 3.8% NIIT)
• Short-term capital gains (held ≤ 1 year): Ordinary income rates
• Long-term capital gains (held > 1 year): Preferential rates (0%, 15%, or 20% + 3.8% NIIT)
• After-tax return on income: R_at = R × (1 - t)
• Capital gains are taxed only at realization, providing a deferral benefit

Tax Drag

The annual cost of taxes on investment returns:

• Tax drag = pre-tax return - after-tax return
• High-turnover funds generate more short-term gains → higher tax drag
• Index funds with low turnover minimize tax drag
• ETFs generally more tax-efficient than mutual funds (in-kind creation/redemption process)

Tax Lot Management

When selling partial positions, the method of selecting which lots to sell affects tax liability:

• Specific identification: Choose exactly which lots to sell
• HIFO (Highest In, First Out): Sell highest-cost-basis lots first to minimize gains
• FIFO (First In, First Out): Default method; may realize larger gains on older lots
• Tax-optimal: Select lots to minimize current-year tax liability considering holding period and gains/losses

Roth Conversion

Convert Traditional IRA/401k assets to Roth, paying ordinary income tax now for tax-free growth and withdrawals later:

• Breakeven analysis: Conversion is beneficial if current marginal tax rate < expected future marginal tax rate
• Factors favoring conversion: Long time horizon, low current income year, expectation of higher future rates, desire to reduce future RMDs, estate planning benefits
• Partial conversions: Convert just enough to fill current tax bracket ("bracket stuffing")
• Tax on conversion: conversion amount × current marginal rate

Required Minimum Distributions (RMDs)

Mandatory annual withdrawals from tax-deferred accounts (Traditional IRA, 401k) beginning at age 73 (under SECURE 2.0):

• RMD = account balance (Dec 31 prior year) / distribution period (from IRS Uniform Lifetime Table)
• Failure penalty: 25% excise tax on shortfall (reduced from prior 50%)
• RMDs are taxed as ordinary income and can push retirees into higher brackets
• Roth IRAs have no RMDs during the owner's lifetime

Withdrawal Sequencing

The order of withdrawals from different account types in retirement:

• General rule: Taxable → Tax-deferred → Roth (preserves tax-free growth longest)
• Optimized approach: Withdraw from taxable first, then fill low tax brackets with tax-deferred withdrawals, use Roth to avoid bracket jumps
• Dynamic strategy: Adjust each year based on income, deductions, and bracket thresholds

Charitable Giving Strategies

• Donate appreciated stock: Avoid capital gains tax and deduct full fair market value (must be held > 1 year)
• Qualified Charitable Distributions (QCDs): Donate up to $105,000/year directly from IRA to charity (counts toward RMD, excluded from taxable income); available at age 70½+
• Donor-Advised Funds (DAFs): Bunch multiple years of donations for itemized deduction, invest tax-free, distribute to charities over time

Key Formulas

| Formula | Expression | Use Case | |---------|-----------|----------| | After-tax return (income) | R_at = R × (1 - t) | Bond/interest income after tax | | After-tax return (deferred gains) | R_at = (1 + R)^n × (1 - t_cg) + t_cg)^(1/n) - 1 | Unrealized equity with deferral benefit | | Tax-loss harvesting value | TLH_value = loss × marginal_tax_rate | Immediate tax benefit of harvesting | | Roth conversion breakeven | t_now < t_future | Convert when current rate < future rate | | RMD amount | RMD = balance_Dec31 / distribution_period | Required minimum distribution | | Points breakeven (charitable) | Tax saved = FMV × t_income + gain × t_cg_avoided | Benefit of donating appreciated stock |

Worked Examples

Example 1: Asset location optimization

Given: $500K in taxable brokerage + $500K in Traditional IRA. Portfolio target: 50% bonds (yielding 5%) and 50% equities (expected 10% total return, 2% qualified dividends). Marginal tax rate: 32% ordinary, 15% LTCG. Calculate: Optimal asset placement and annual tax savings vs naive allocation. Solution:

1. Optimal placement: Bonds ($500K) in IRA; Equities ($500K) in taxable.
2. Naive placement (50/50 each): Taxable has $250K bonds + $250K equities; IRA has $250K bonds + $250K equities.
3. Tax drag — naive: Taxable bonds: $250K × 5% × 32% = $4,000. Taxable equity dividends: $250K × 2% × 15% = $750. Total tax = $4,750.
4. Tax drag — optimal: Taxable equity dividends only: $500K × 2% × 15% = $1,500. Total tax = $1,500.
5. Annual tax savings: $4,750 - $1,500 = $3,250/year (0.325% of total portfolio).
6. Over 20 years compounded, this adds significantly to after-tax wealth.

Example 2: Roth conversion breakeven

Given: Consider converting $50,000 from Traditional IRA to Roth. Current marginal tax rate: 24%. Tax on conversion paid from outside funds. Investment horizon: 20 years. Expected return: 7%. Calculate: Future marginal tax rate at which conversion breaks even. Solution:

1. Cost of conversion now: $50,000 × 24% = $12,000 tax paid today.
2. Traditional IRA path: $50,000 grows to $50,000 × (1.07)^20 = $193,484. After-tax at withdrawal: $193,484 × (1 - t_future).
3. Roth path: $50,000 grows to $193,484 tax-free. Net cost: $193,484 - $12,000 × (1.07)^20 = $193,484 - $46,412 = $147,072 net benefit after accounting for lost growth on tax paid.
4. Breakeven: Set Traditional after-tax = Roth net value. $193,484 × (1 - t_future) = $193,484 - $46,412 → t_future = $46,412 / $193,484 = 24.0%.
5. Conclusion: Breakeven future rate equals the current rate (24%). If the future rate exceeds 24%, the Roth conversion is beneficial. This result holds generally: conversion wins when future rate > current rate, assuming tax is paid from outside funds.

Common Pitfalls

• TLH wash sale violations, including purchases in other accounts, IRAs, or a spouse's account within the 30-day window
• Over-harvesting losses that defer gains to higher tax brackets later (basis step-down compounds)
• Not considering state taxes in asset location decisions — state tax treatment varies significantly
• Ignoring the tax benefit of donating appreciated securities vs cash (avoids capital gains and gets full deduction)
• RMD-driven forced selling at inopportune times — plan withdrawals ahead of deadlines
• Roth converting too aggressively and pushing into a higher bracket in the conversion year
• Forgetting the 3.8% Net Investment Income Tax (NIIT) above income thresholds
• Not coordinating tax strategy across spouses' accounts

Cross-References

• investment-policy (wealth-management plugin, Layer 5): Tax constraint in IPS governs asset location and turnover management
• performance-attribution (wealth-management plugin, Layer 5): After-tax return attribution requires tax-aware calculations
• debt-management (wealth-management plugin, Layer 6): Mortgage interest deductibility interacts with tax planning
• savings-goals (wealth-management plugin, Layer 6): Account type selection (Roth vs Traditional) is a core tax decision
• liquidity-management (wealth-management plugin, Layer 6): Tax implications of accessing different account types affect liquidity planning
• tax-loss-harvesting (wealth-management plugin, Layer 5): dedicated TLH workflow skill with detailed candidate identification, wash-sale tracking, and execution planning
• financial-planning-workflow (advisory-practice plugin, Layer 10): tax-aware strategies are core recommendations in comprehensive financial plans

Reference Implementation

See scripts/tax_efficiency.py for computational helpers.