Use Variable Sweeps

A sweep reveals how one assumption changes the result

Variable Sweeps repeat an analysis across a range of values for one supported input, such as retirement age, Social Security timing, desired income, longevity, or historical starting period. Holding the rest of the plan constant makes thresholds, flat regions, and tradeoffs easier to see than creating many separate scenarios by hand.

A sweep is most useful when the values represent genuine choices or credible uncertainty. A wide range of impossible retirement ages or unsupported spending levels may produce a colorful report without improving the decision.

Use a What-if when several things must change together

Choose a sweep when the question is “How sensitive is the plan to this one value?” Use a named What-if when the real alternative changes several connected facts—for example, retiring later may also change salary, contributions, healthcare, pension service, and spending.

Select a range that includes the current value and plausible alternatives. Values close to a threshold deserve neighboring points; a coarse step can make the cutoff appear more precise than the analysis supports.

Run the deterministic view first when the question concerns annual mechanics or a first shortfall. Add probability analysis when uncertainty and downside resilience are central.

Set the range before looking for the answer

Select one supported variable, define the minimum, maximum, and step, and confirm the current-plan row. Keep the saved plan, strategy, horizon, balance date, and other assumptions fixed. For stochastic sweeps, use consistent model settings and enough trials to avoid treating sample noise as a threshold.

Historical-period sweeps replay specific historical windows and therefore are not combined with a stochastic return model. The purpose is to compare actual sequences under the same plan, not to mix them with newly generated shocks.

Do not apply a value directly from the most attractive row. First decide whether it is feasible, whether connected assumptions would also change, and whether the neighboring values tell a stable story.

Look for regions and tradeoffs, not a magic point

Find the first shortfall, meaningful improvement, or plateau. Examine several adjacent rows to see whether the outcome changes gradually or flips because of an annual transition. A one-year retirement change can coincide with another benefit or tax event, so inspect Projection before calling the cutoff causal.

Goal-income sustainability means the modeled plan avoids annual cash shortfall under the sweep’s assumptions. Ending wealth is shown separately from spendable resources because restricted HSA and 529 balances do not serve ordinary spending in the same way.

For a chosen candidate, create or update a What-if with the complete real-world changes and rerun the main reports. The sweep isolates one variable; the scenario should describe the actual alternative.

One-variable sensitivity is not global optimization

A sweep does not discover the best combination of retirement age, spending, allocation, benefits, taxes, and behavior. It cannot prove that a selected value is attainable or personally acceptable.

Use it to understand sensitivity and narrow a decision. Preserve practical constraints and connected assumptions in the final What-if rather than adopting the row as a complete plan.

When can I retire?

Open Variable Sweeps and choose My retirement age. The deterministic sweep shows how each tested age changes ending resources; probability analysis applies matching uncertain market paths to every age. Look for the earliest age that meets the success target you intentionally selected, then compare it with the next few ages rather than treating one threshold as exact. When the goal is substantially earlier retirement, people often call the broader approach FIRE—Financial Independence, Retire Early—but YARCalc still tests the saved dates, spending, and resources rather than assigning a FIRE label.

Verify that candidate in Projection and Stochastic Analysis. Pay special attention to the years between work income and Social Security or pensions, healthcare before Medicare, contribution changes, taxes, early withdrawals, downside balances, and any spending reductions. The candidate age answers the saved plan—not a generic household with the same account total.

A successful row is evidence for a retirement-date conversation, not permission or a guarantee. Revisit the answer after a major balance change, spending decision, job change, benefit estimate, or shift in the planning horizon.

Can I retire at a specific age?

Choose My retirement age in Variable Sweeps and find the requested age in the annual range. Read that row beside the ages immediately before and after it. If the age is earlier than the person’s current age or later than the saved planning horizon, correct the question or the underlying dates before interpreting the report.

For the requested age, compare probability of success, downside outcomes, shortfall timing, bridge withdrawals, healthcare transitions, and ending resources. An age can look workable in a fixed-return projection yet remain fragile when poor early market paths are included.

Use a separate What-if when retiring at that age also changes part-time work, insurance, contributions, a move, or spending. A one-variable sweep should not be asked to represent a life transition with several connected changes.

How much can I safely spend?

Open Variable Sweeps and choose Annual spending. Probability analysis compares calculated spending levels using matching market paths. Find the highest tested level that meets the success target, then review nearby rows and the difference between essential and discretionary spending.

A useful spending answer includes more than success probability. Inspect downside balances, the first shortfall year, modeled reductions, taxes, early-retirement withdrawals, healthcare costs, and the resources remaining late in life. If the suggested level is far from the current budget, verify that the saved budget is complete before changing it.

“Safe” is shorthand for meeting a chosen standard under stated assumptions. It does not mean guaranteed. Use the sweep to define a reasonable range, a baseline budget, and adjustments the household could actually make when results deteriorate.

When should I claim Social Security?

Run My Social Security start age in Variable Sweeps, and run the spouse sweep separately when the plan includes a spouse. Start with official benefit estimates and confirm that YARCalc’s claiming-date adjustment is appropriate for the estimate you entered.

Compare the portfolio withdrawals needed while benefits are delayed, taxes after benefits begin, survivor resources, required distributions, and ending balances. For a couple, the strongest individual row may not be the strongest household combination because the larger benefit can affect survivor income.

The sweep identifies financially interesting ages under the saved assumptions. It does not establish eligibility, earnings-history corrections, family-benefit rules, or the final amount the Social Security Administration will pay. Verify a candidate with official records before acting.

What if I live longer than expected?

Create a Planning age What-if and choose a minimum age for each person. The starter extends shorter saved lifespans and does not shorten a person already planned beyond that age. Use a death-age sweep when the question is how individual ages change results across a range.

Compare later withdrawals, required distributions, Social Security and pensions, survivor filing years, healthcare spending, depletion, and legacy. For couples, a long survivor period can matter more than simply adding the same years to both lives.

A minimum planning age is a stress assumption rather than a prediction. Test more than one horizon when the decision is sensitive to a single late year.