Schwab Lifetime Adjustable Income: Flexible Withdrawal Rules Based On Portfolio Survival Chances

One of the perpetual debates in retirement planning circles is withdrawal rates, AKA how much monthly income can you take from a portfolio. Once you nail down a withdrawal rate and retirement spending target, then you get Your Number – how much you need to have saved to retire (after backing out Social Security and other income streams). It’s common to start with the static 4% rule, but that rule also includes some drawbacks. An alternative is a flexible withdrawal rule that adjusts based on market returns. When your portfolio grows, you can spend a little more. If it shrinks, you cut back a little. Sounds reasonable, right?

However, I haven’t seen many real-world examples of flexible withdrawal rules. Schwab has helpfully outlined one proposed method in this memo: Lifetime Adjustable Income vs. the 4% Rule: Can You Spend More in Retirement with Less Risk? This provides the underlying basis behind their robo-advisor feature called Intelligent Income where you can pick a comfort level and the software will tell you how much you can withdraw each year and from which type of account (IRA, Roth IRA, taxable, etc).

In this memo, we compare a flexible withdrawal strategy to the static 4% rule. We recommend a lifetime adjustable income strategy, described in this paper, that can be put into action using an annually updated financial plan, using technology or an advisor. Doing so may help increase spending early in, and over a long, retirement and help ensure your money lasts.

Here’s their example structure for flexible withdrawals:

• Set an initial withdrawal rate that delivers an 80% probability of success (savings lasting).
• Adjust spending amounts after each year based on if the probability of savings lasting falls outside the range you decide: here it is below 75% or above 99%. If these thresholds are crossed, increase or decrease spending by the amount that brings the financial plan back to a 99% probability of savings lasting. This results in fewer but more drastic cuts.
• Add “guardrails”. A minimum and maximum acceptable annual (real) spending amount of $25,000 and $60,000, respectively, meaning that we will always withdraw at least $25,000 (or at most $60,000).

Using these flexible rules, the initial withdrawal rate was about $43,000 instead of $40,000. Across all of the simulated scenarios, the average annual withdrawal was basically 20%, or $10,000 a year, higher: $50,000 a year instead of the $40,000 a year (in today’s dollars). Even better, the likelihood of running out of money dropped.

However, you must look past the averages and see that you are now exposed to the extremes. Look at that wide expanse of grey. A significant number of the scenarios involved some extended deep cuts to spending, hitting and hovering just above the $25,000 minimum guardrail. You’ll have to decided if you like this trade-off between probably getting more income but possibly enduring some big cuts. This is why many financially-conservative people would prefer to simply start out at a lower 3% or 3.5% withdrawal rate and adjust upwards if the portfolio keeps growing.

In any case, I found it interesting that Schwab used the probability of portfolio survival rate as the factor used to adjust withdrawal rate. DIY investors can implement a similar system themselves. Here are some tools to estimate portfolio survival probability:

• Vanguard has a very simple one.
• cFIREsim and FIREcalc allow you to enter a variety of variables manually.
• Personal Capital remembers and tracks my actual portfolio and updates this number automatically. That part is free but also offers an optional paid financial advice tier.