About Strategy Compare

A Coast-FIRE retirement strategy planner that funds a fixed, configurable post-tax spending curve. Compare contribution stop strategies, lending acceleration, and Solo 401k funding under deterministic, Monte Carlo, and historical return sequences.

What This Tool Does

Strategy Compare models five canonical retirement approaches side-by-side through one shared financial engine. The LCS spend phase follows the requested start, peak, sustain, taper, and floor amounts; it never silently substitutes a larger “maximum affordable” budget. Each strategy represents a different contribution and lending policy:

Strategy	IRA	401k/457	Solo 401k	Lending	Philosophy
Full Plan	max	to retire	to retire	flat	Max everything, fund Solo from lending profit
Keep Maxing (no lending)	max	to retire	stop now	off	Max tax-advantaged, skip lending complexity
Coast Now	stop now	stop now	stop now	off	Zero new contributions — let compounding do the work
Solo Only	stop now	stop now	to retire	flat	Only the lending→Solo pipeline keeps running
Scale Lend	max	to retire	to retire	scales w/ brokerage	Lending capital tracks portfolio, more Solo room

"max" = contribute until model end age (98); "to retire" = stop at retirement age (55); "stop now" = halt at current age (33); "flat" = $300K lending capital fixed; "scales w/ brokerage" = lending capital maintains initial ~27% ratio to brokerage balance.

Understanding the Spending Pattern Framework

All strategies in this tool follow a common spending pattern framework built around three key concepts:

1. End-of-life minimum: A spending floor that must be sustainable through your expected lifespan (typically based on essential expenses like healthcare and basic living costs)
2. Spending start: The age at which you begin spending above this floor
3. Spending pattern: How your spending above the floor changes over time - which may include a period of peak spending (often 10 years) that can be adjusted based on your surplus savings

Think of it like this: First, you secure your basic needs for life. Then, with any additional savings, you decide when to start enjoying extra spending and how long to sustain higher spending levels. The "possibly peak spending for 10 years" concept refers to a common pattern where you might have a distinct period of elevated spending (for travel, hobbies, etc.) before potentially settling into a lower long-term spending level.

Different strategies approach this framework differently:

• Coast Now: Starts spending above the floor as early as possible, letting compounding do the work
• Full Plan / Scale Lend: Delays spending above the floor to build a larger asset base first, then can sustain higher spending
• Solo Only: Focuses on building the Solo 401k pipeline first before spending above the floor
• Keep Maxing (no lending): Maximizes traditional retirement accounts while skipping the lending complexity

The key insight is that with more surplus savings (total savings minus the present value of your lifelong floor), you can either start spending earlier, spend at a higher level, or extend the duration of your preferred spending pattern.

Earliest Retirement Age by Target Spend (All Strategies)

Computed on page load. “100%” means every year in one deterministic projection funds at least 99% of that year's curve target and the portfolio never depletes. It is not a probability or confidence score; see Overview for Monte Carlo and historical sequence tests.

Sustain Phase Duration by Spend Start Age

The "health" spend curve has: delay → ramp-up → sustain → taper. Sustain is capped at spendSustainYears (default 15). At later start ages, sustain consumes a larger % of the remaining window.

Solo 401k Pipeline — Yearly Breakdown (Full Plan, Age 55 Start)

Lending is Schedule C income for a single-member LLC: net profit pays self-employment tax and progressive federal/NC income tax. Solo funding is capped by adjusted eligible business compensation and the annual-additions limit. The model fills unused employee-deferral room, then the sole-proprietor employer contribution, then voluntary after-tax contributions with immediate in-plan Roth conversion. With Scale Lend, lending capital scales with brokerage.

Portfolio Composition at Key Ages (All Strategies, Age 55 Start)

With default params ($1.695M start, including separate $200K Roth 401(k) and $160K Roth 457(b) balances, at 9%/9% growth), contribution differences are compared against compound growth. Table shows Brokerage / IRA / combined 401k+457 / Solo % and total portfolio value.

Withdrawal Rate Trajectory (Full Plan, Age 55 Start)

WR = net portfolio need ÷ total pool at start of year. The traditional 4% line is a reference only; the full cash-flow and sequence tests determine whether the requested curve is funded.

Social Security Impact (Full Plan, Age 55 Start)

SS claim age applies the statutory early-claim reduction or delayed credits around the worker's actual FRA. Adding SS can reduce portfolio need. PIA uses the 2008–2025 earnings history plus a fixed $120,000 nominal W-2 only through the modeled final work year. The default is a hard OFF and full scheduled benefits are used when enabled.

Why the Gap Shrinks So Much

• Cash-flow math: A lower requested curve needs less after-tax income and less portfolio draw in every affected year, so it can move the fixed-return break-even earlier.
• Spend curve shape: The default health-aware curve begins at $100K, spends at peak ($200K) for 15 years, then tapers linearly to the $100K end-of-life floor over 10 years, holding the floor for the remaining decades. Lowering the target shifts the entire curve down proportionally.
• Nest-egg floor is fixed: The final-year healthcare guard is identical at both targets. Relative to the lower spending target it is a larger share of annual spend, yet the portfolio remains above the guard in both cases.
• Sequence risk is separate: The deterministic age answers the fixed-return math. Overview then tests that age against Monte Carlo paths and every complete historical rolling window in the 1928–2025 dataset.

Withdrawal Order (Waterfall)

Each year's net withdrawal is netW = max(0, spend − incomeTotal), where spend is the post-tax all-in budget (healthcare already inside it) and incomeTotal = W-2 net + pension + rental income + Social Security (if enabled). The net need is funded in strict order:

1. Brokerage (taxable — realized gains pay marginal LTCG, traced pro-rata against cost basis; gross pulled > net by the tax)
2. Roth IRA (contribution basis first before 59½; nonqualified earnings are taxed and penalized)
3. Roth 457(b), then Roth 401(k) (designated-Roth withdrawals are pro rata before 59½; the 457(b) has no modeled 10% early penalty)
4. Roth Solo 401(k) (designated-Roth pro-rata rules before 59½)

Qualified Roth withdrawals are tax-free. Unknown starting contribution basis defaults to $0 so the model does not optimistically treat legacy Roth earnings as immediately accessible.

Social Security — Real PIA, Not a Guess

The model computes PIA from the 2008–2025 earnings history, AWI-indexed to age-60 wages, top-35 years averaged into AIME, then the 90/32/15 bend-point formula. Future covered earnings are exactly $120,000 nominal through the final modeled work year and $0 afterward. Claiming reductions/credits use the worker's actual FRA. Default is OFF and contributes exactly $0 until enabled.

Lending → Solo 401k Pipeline

This is the unique accelerator. Schedule C net profit is gross lending yield less the effective margin cost, then self-employment and progressive income taxes apply. Solo contributions can never exceed adjusted eligible business compensation or the annual-additions ceiling ($72,000 in 2026). While the W-2 401(k) uses the shared employee-deferral limit, remaining Solo room is filled with employer and voluntary after-tax contributions; after-tax amounts are immediately converted in-plan to Roth.

How to Use the Tool

• Overview page (/strategy-compare/overview/): Every strategy's earliest deterministic age plus Monte Carlo and historical sequence pass rates. Toggle Today$/Nominal$ and Social Security.
• Planner page (/strategy-compare/): Full interactive model. Adjust balances, contribution basis, growth, tax, lending, the spending curve, and retirement age. Every change is carried in the URL state.
• Charts & tables: Total pool, account breakout, post-tax spend vs target, withdrawal rate trajectory. Click any cell for detailed tax, funding-waterfall, pension, and Social Security math.
• Presets: Five chips at top of Controls apply the canonical strategies instantly.

Taxes

Inflation

Assumptions & Limitations

• Single filer — exact 2026 federal brackets/limits initialize the model; future federal bracket thresholds are assumed to grow 3%. NC is 3.99%. AMT, QBI, itemized deductions, tax credits, and detailed Schedule E depreciation/passive-loss rules are not modeled.
• Household-wide progressive tax — W-2, TSERS, Schedule E rental, Schedule C lending, taxable Social Security, and portfolio income are combined once; payroll, SE, NC, LTCG, and NIIT calculations are separate and no flat W-2 tax shortcut is used.
• SS wage base frozen — past 2026, the SS taxable wage cap stays at $184,500 (not inflated). Conservative by design; non-binding at current W-2 income.
• All tax-advantaged buckets are Roth — qualified withdrawals are tax-free; early-access basis/pro-rata rules are modeled conservatively. Exact five-year contribution/conversion cohorts are not.
• No RMDs — IRA/401k balances grow untouched until drawn in waterfall order.
• Returns — the deterministic model uses 9% nominal returns across all accounts (brokerage, IRA, and employer 401(k)/457 plans). After the last W-2 year the employer-plan balances roll to the same 9% self-managed rate (no change in the rate, just the wrapper). Overview adds seeded Monte Carlo and historical 1928–2025 rolling-sequence tests.
• Healthcare — payroll premiums are deducted from W-2 income; the household out-of-pocket reserve is separate; DOT retiree health applies before Medicare and Medicare thereafter (premium estimates cover user + spouse and inflate at 5%). Long-term care is not modeled.
• Pension — NC TSERS formula (years of service × 1.82% × four-year AFC), with service frozen at separation and official unreduced, early-reduced, and vested-deferred age gates. The household projection uses Option 2 (100% survivor) with a conservative same-age factor; exact payment-option dollars must be replaced with an ORBIT estimate before an actual retirement election.
• Rental income — starts at the configured year and inflates at 3%; the input is already Schedule E profit after vacancy, maintenance, management, and other property costs.
• Lending — assumes margin loan always available at stated rate, no margin calls, no regulatory changes.

Source: /var/www/html/strategy-compare/about/index.html · Engine shared with /strategy-compare/ planner and /strategy-compare/overview/ · All client-side, no backend.