Optimal sequencing of withdrawals is a retirement decumulation method for choosing which accounts to liquidate, and when, to meet spending needs while reducing taxes. Common orders include taxable-first, IRA-first, filling a tax bracket with IRA withdrawals, and Roth conversion. The choice can materially change how long savings last. section 1.2.2 section 9.0
The central trade-off is between account tax efficiency and tax-bracket management. A taxable account can suffer tax drag from interest income and realized capital gains, while IRA and Roth balances can have higher assumed after-tax growth. Tax-rate expectations also matter: a traditional IRA is preferable to Roth when future tax rates are lower, while Roth is preferable when future rates are higher; with unchanged rates, their withdrawal order does not matter under the stated comparison. section 9.1.1 section 9.2.1
A practical analysis proceeds by:
- Specify account balances, real after-tax returns, annual spending, deductions, tax brackets, and a maximum horizon. section 9.2.1 section 9.2.2
- Compute federal tax from taxable income, then solve for the gross IRA distribution that supplies a desired after-tax spending amount. section 9.2.2
- Simulate balances year by year for each account order, withdrawing from accounts in sequence and comparing the years assets support spending. section 9.2.2
- Extend the comparison when needed for RMDs, capital gains, state taxes, inheritance, and beneficiary tax brackets. section 9.0 section 9.3.2
Taxable first versus IRA first
With $2 million taxable, $1 million IRA, no Roth balance, $120,000 annual spending, and assumed real returns of 3% taxable and 4% for the IRA, an IRA-first sequence lasts 40.0 years. Changing only the order to taxable, IRA, Roth lasts 48.7 years. Taxable-first depletes the less tax-advantaged account first, allowing the IRA to grow without the modeled taxable-account drag, though it does not keep tax brackets stable over time. section 9.2.1 section 9.2.4
Results depend on assumptions rather than providing a universal order. Early comparisons deliberately ignore realized and unrealized capital gains, asset location, tax-loss harvesting, RMDs, and inheritance effects to isolate sequencing. Inheritance can reverse a preferred order: when an owner faces a lower bracket than beneficiaries, depleting traditional IRA assets or converting to Roth may help; when the owner faces a higher bracket, retaining the IRA for heirs may be preferable. section 9.2.1 section 9.3.2
Table 9.3 Comparison of the first two sequencing strategies
| Strategy | Number of years money lasts |
| IRA first, then taxable | 40.0 |
| Taxable first, then IRA | 48.7 |
Compare the modeled longevity difference between IRA-first and taxable-first withdrawal orders. section 9.2.4
