Take your minimum required distributions (MRDs ).

If you are age 70½ or older, make sure you know which of your accounts require such distributions and how large those distributions need to be, then meet the deadlines to avoid penalties.

  Learn about Taking Withdrawals After Age 70½.

Liquidate loss positions in taxable accounts.

Some investments in your taxable accounts may be worth less than their tax basis (generally the amount you paid to acquire them). In addition to offsetting (netting) realized losses against realized gains, at the federal level you can usually use up to $3,000 ($1,500 for married couples filing separately) of net losses each year to offset ordinary income such as interest, salaries, and wages. Unused losses can usually be carried forward for use in future years.

Sell assets in taxable accounts that will generate neither capital gains nor capital losses.

Such assets might include money market funds or other cash-equivalent investments. If your withdrawals largely come from cash-equivalent investments, be sure to leave sufficient liquid assets investments intact to cover any short-term financial emergencies and be especially mindful of potential rebalancing issues (as discussed above).

Withdraw money from taxable accounts or tax-deferred saving vehicles funded with at least some nondeductible (or after-tax) contributions, such as variable annuities and Traditional IRAs.

Fidelity's research has found that the choice depends on the circumstances, and in some cases, it might make more sense to tap the tax-deferred vehicle first. Assuming there is a significant difference in the basis-to-value ratio of the assets to be liquidated in two accounts (in other words, the tax basis of the assets divided by their current value), the best tactic for choosing between these two types of withdrawals is often to liquidate the assets with the higher ratio. That is, the assets that have generated the smallest gain or the largest loss as a percentage of their basis. If the basis-to-value ratio of the assets to be liquidated in each account is relatively low as a percentage of their basis, such as in the case of significant investment gains, it often will be preferable to liquidate the assets in the taxable account. Conversely, if the basis-to-value ratio of the assets to be liquidated in each account is relatively high, it may be preferable to liquidate assets in the tax-deferred account. Note that tax-deferred accounts are generally subject to certain aggregation requirements when allocating basis. Consult with your tax adviser for additional details.

When liquidating gain positions in taxable accounts, it usually makes sense to sell assets with long-term capital gains first, since they should be taxed at lower rates than short-term gains are. In addition, consider liquidating assets that are likely to generate smaller taxable gains when expressed in dollar terms.

If you are thinking of leaving assets to beneficiaries, this fourth guideline may not serve you well. See About Estate Planning for more information.

Withdraw money from tax-deferred accounts funded with deductible (or pre-tax) contributions such as 401(k)s and Traditional IRAs or tax-exempt accounts such as Roth IRAs.

Fidelity's research suggests that, contrary to popular wisdom, it may not make much difference which account you tap first within this category assuming (1) all withdrawals from any tax-deferred accounts funded with fully deductible (or pre-tax) contributions are taxed at the same rate throughout your retirement and (2) when you withdraw money from the tax-deferred account funded with fully deductible (or pre-tax) contributions, you'll have to take out enough to cover taxes. As a result, you'll have less money continuing to grow on your behalf than if you had taken a qualified tax-exempt distribution of a smaller sum from a tax-exempt account.

If you believe that withdrawals you make may be subject to different tax rates over the course of your retirement (for example, based on changes to tax laws or to your levels of income) you may be better off liquidating one type of account within this fifth guideline before another. For example, it may make more sense to leave your Roth account intact if you thought your ordinary income tax rate was likely to rise in later years, increasing the value of the Roth's tax exemption. Estate planning considerations may also significantly impact this guideline.