This is part of a series on tax-efficient portfolio construction. Each post in this series explores a different dimension of tax efficiency — some build directly on previous posts, others stand on their own. If you are new here and want the broader context first, start with our Investment Philosophy page. If you are ready to dig in, read on.
Image generated with AI assistance from ChatGPT.
Summary — For Those Who Want the Short Version
What changed
- Same investments. Same savings rate. Same allocation glide path.
- Only placement differs.
Who this applies to
- A hypothetical Bay Area couple, both 45, with $2.05M across three account types
What happened
- At retirement (age 66): the optimized scenario is ahead by $161,011
- The gap narrows in early retirement, then accelerates — reaching $2,099,399 by age 95
Why it matters
- Lower taxes during accumulation
- Smaller RMDs → less tax later
- Two scenarios modeled in Right Capital: one with uniform allocation across all accounts, one with deliberate asset location
- The acceleration in late retirement is driven by a smaller 401(k) in the optimized scenario, meaning lower forced RMDs and less ordinary income tax in later years
- This is just one layer of tax efficiency. Additional layers are explored in other posts in this series.
Want the full detail? Read on.
The Result First
A hypothetical Bay Area couple — both 45, both high earners — makes one change to their financial plan.
- They do not change what they invest in.
- They do not change how much they save.
- They do not take more risk.
- They do not time the market.
- They change only where their investments sit across their accounts.
Over 50 years — from age 45 to 95 — that one change could be worth more than $2.1 million.
- This is not a small optimization.
- It’s a structural decision that compounds quietly for decades.
This post walks through exactly how that happens, why the gap starts small and grows dramatically, and what it means in practice. All scenarios are modeled in Right Capital financial planning software using the assumptions detailed below.
The Hypothetical Couple — Meet the Nguyens
The Nguyens are a fictional couple. Any resemblance to actual clients is coincidental — this is a hypothetical illustration for educational purposes only.
Both are 45 years old. They live in the Bay Area, earn $600,000 per year combined, and plan to retire at 66. Their financial plan runs to age 95.
They have two children — ages 8 and 10 — and are thoughtful, disciplined savers.
They’re high-income professionals—typical of many Bay Area households—busy, disciplined, and doing most things “right.”
Their current accounts:
| Account | Balance |
|---|---|
| Taxable brokerage | $1,000,000 |
| 401(k) | $800,000 |
| Roth IRA | $250,000 |
| Total | $2,050,000 |
They also have 529 college savings accounts — $50,000 for Child 1 and $40,000 for Child 2 — with ongoing contributions.
Key Assumptions
All scenarios use identical assumptions. The only thing that changes between the base scenario and the optimized scenario is how investments are allocated across account types.
Profile
| Detail | Value |
|---|---|
| Ages | Both 45 |
| Retirement age | 66 |
| Plan end | Age 95 |
| Combined income | $600,000/year |
| Social Security claiming age | 70 for both |
Contributions
| Account | Amount |
|---|---|
| 401(k) per person | $24,500 (2026), increasing to $31,000 at age 50 |
| 401(k) combined | $49,000 (2026), $62,000 from age 50 |
| Backdoor Roth per person | $7,500 (2026), increasing with catch-up limits |
| Taxable account | Surplus/deficit cashflow after all expenses and contributions |
Annual Expenses
| Expense | Amount |
|---|---|
| General living expenses | $12,000/month |
| Home insurance | $6,000/year |
| Home maintenance | $20,000/year |
| Property tax | $25,000/year |
| Child 1 expenses (through 2033) | $18,000/year |
| Child 2 expenses (through 2035) | $18,000/year |
| Pretax deductions incl. healthcare | $1,000/month |
| Mortgage (ends 2050, balance $1.4M at 3%) |
College Planning
| Detail | Value |
|---|---|
| Child 1 college starts | 2034, $50,000/year (today's dollars) |
| Child 2 college starts | 2036, $50,000/year (today's dollars) |
| 529 ongoing contributions | $7,000/year per child until age 20 |
Investment Return Assumptions (Hypothetical)
| Asset Class | Hypothetical Expected Return | Notes |
|---|---|---|
| Equity (US & ex-US) | 7% total | 2% dividend, 5% appreciation |
| Total Bond Market ETF | 3.65% | 70% Treasury × 3.5% + 30% Corporate × 4% |
| Qualified dividends | 75% of dividend income | |
| Long-term capital gains | 100% of gains realized | Buy-and-hold assumption |
Glide path: 70/30 stocks/bonds today → gradually decreasing → 50/50 at end of plan (age 95). Applied identically in both scenarios.
Tax Assumptions
| Tax | Rate | Notes |
|---|---|---|
| Federal income tax | 35% | Pre-tax 401(k) contributions bring effective bracket to 35% |
| California state income tax | 9.3% | Working years |
| Net Investment Income Tax (NIIT) | 3.8% | Applies at $600k income level |
| Tax on ordinary investment income | 48.1% | Federal + CA + NIIT on bond interest |
| Qualified dividend / LTCG rate | 20% federal + 9.3% CA + 3.8% NIIT | ~33.1% combined |
Inflation Assumptions
| Category | Rate |
|---|---|
| General inflation | 2.5% |
| Education inflation | 5.0% |
| Tax inflation | 2.5% |
| Healthcare cost inflation | 5.0% |
| Social Security | 2.5% |
| Annual salary increase | 2.5% |
Two Scenarios — One Difference
Base Scenario: Pro-Rata Allocation
The same 70/30 allocation uniformly across all accounts — stocks and bonds distributed proportionally everywhere, without deliberate consideration of which account type holds which investment.
Optimized Scenario: Asset Location Strategy
Same investments. Same overall glide path. Same contributions. Same expenses.
The only change: investments are placed deliberately across accounts based on their tax characteristics. The approach follows a logical sequence:
- Equities are placed first in the taxable account — stock appreciation is deferred until sale and taxed at favorable long-term capital gains rates, making taxable a relatively efficient home for equities
- Remaining equity allocation fills the Roth IRA next — growth inside a Roth is permanently tax-free, which is especially valuable for higher-returning assets
- Any remaining equity goes into the tax-deferred 401(k) — once the desired equity allocation is fully placed using the order above, the remaining capacity in all accounts is filled with fixed income, in the reverse order: tax-deferred first, then Roth, then taxable
The result: fixed income — which generates interest taxed annually at ordinary income rates — is sheltered inside tax-advantaged accounts as much as possible. Equities — which grow mostly through deferred appreciation — are placed where that deferral is most effective.
The overall allocation follows the same glide path in both scenarios. Only the placement differs.
The Results
Summary Comparison
| Year | Age | Base Scenario | Optimized Scenario | Difference | % Difference |
|---|---|---|---|---|---|
| 2027 | 46 | $2,340,348 | $2,344,215 | $3,867 | 0.2% |
| 2031 | 50 | $3,307,344 | $3,329,292 | $21,948 | 0.7% |
| 2036 | 55 | $4,759,882 | $4,813,455 | $53,573 | 1.1% |
| 2041 | 60 | $6,874,793 | $6,974,345 | $99,552 | 1.4% |
| 2046 | 65 | $10,231,718 | $10,400,850 | $169,132 | 1.7% |
| 2047 | 66 — Retirement | $10,339,377 | $10,500,388 | $161,011 | 1.6% |
| 2051 | 70 | $10,941,549 | $11,058,367 | $116,818 | 1.1% |
| 2056 | 75 | $13,252,145 | $13,351,841 | $99,696 | 0.8% |
| 2061 | 80 | $15,478,330 | $15,851,081 | $372,751 | 2.4% |
| 2066 | 85 | $17,868,466 | $18,735,325 | $866,859 | 4.9% |
| 2071 | 90 | $20,408,550 | $21,978,086 | $1,569,536 | 7.7% |
| 2076 | 95 — End of Plan | $15,256,385 | $17,355,784 | $2,099,399 | 13.8% |
Hypothetical illustration modeled in Right Capital. Does not represent actual client results.
What stands out from this table
- The advantage is barely noticeable for the first decade
- It actually shrinks after retirement — which surprises most people
- Then it accelerates sharply after age 80, driving the majority of the $2.1M difference
- In other words: this is not a linear benefit—it’s a delayed compounding effect driven by taxes
Why the Gap Behaves the Way It Does
The numbers tell a story that deserves explanation — because the gap does something unexpected in the middle of the plan.
Phase 1: Small but Growing (Ages 45–65)
During the accumulation years, the gap starts nearly invisible — just $3,867 at age 46 — and grows steadily to $169,132 by retirement at 65. The mechanism is straightforward: bond interest in the base scenario is taxed annually at 48.1% inside the taxable account. In the optimized scenario, that same interest compounds untaxed inside the 401(k). The difference is modest each year but accumulates steadily over two decades.
Phase 2: The Temporary Narrowing (Ages 66–75)
Here is something worth acknowledging directly: the gap actually narrows in early retirement — from $169,132 at age 65 down to $99,696 by age 75. This is not a modeling error. It happens for a specific reason.
In the base scenario, stocks are held inside the 401(k) during accumulation because the allocation is uniform across all accounts. In early retirement, those stocks continue growing inside the 401(k), temporarily keeping the base scenario competitive. The optimized scenario holds fewer stocks in the 401(k) — equities are concentrated in taxable and Roth — so the 401(k) balance in the optimized scenario grows more slowly in early retirement.
This dynamic reverses as time passes. The tax drag on bond interest in the base scenario continues compounding. Required Minimum Distributions begin at age 73, forcing taxable withdrawals from a large 401(k) that holds a proportionally larger stock allocation. The optimized scenario's smaller 401(k) produces smaller RMDs and correspondingly less ordinary income tax in later years. By age 80 the optimized scenario has pulled decisively ahead and the gap accelerates from there.
Phase 3: Acceleration (Ages 75–95)
From age 75 onward the gap grows dramatically — from $99,696 at 75 to $372,751 at 80, $866,859 at 85, $1,569,536 at 90, and $2,099,399 at 95.
Two forces compound simultaneously. First, the portfolio is significantly larger by this stage — the same proportional difference translates to far larger absolute dollar amounts than in the early years. Second, the account composition diverges meaningfully in late retirement: the base scenario's larger 401(k) generates substantial RMD-driven ordinary income each year, while the optimized scenario carries a lighter and more flexible tax profile through the later years of the plan.
This Is Just One Layer
This post covers a single concept: asset location. Same investments, same savings rate, same allocation glide path — just placed more deliberately across accounts.
Tax-efficient portfolio construction involves multiple dimensions beyond this one. Additional layers — explored in other posts in this series — address other aspects of how a portfolio can be structured to reduce tax drag over time.
What This Means in Practice
The Nguyens are a hypothetical couple. Any individual's situation will look different — different account balances, income levels, tax rates, time horizons, and family circumstances.
But the underlying principle is broadly applicable: when multiple account types exist, the placement of investments across those accounts is a variable that affects after-tax outcomes — meaningfully so over a long time horizon, as this illustration suggests. Not because of a single decision point—but because of how that decision compounds year after year.
A few questions that may be worth considering:
- Is the current allocation distributed uniformly across all accounts, or has placement been deliberately considered?
- Are bonds or bond funds currently held in a taxable account where interest is taxed annually at ordinary income rates?
- Have all accounts been reviewed together as a unified picture rather than managed independently?
These are the kinds of questions that tend to surface in a comprehensive financial planning engagement — not a one-time portfolio check.
- Schedule a free conversation →
- Read how we think about tax efficiency overall →
- Part 2: Tax-Loss Harvesting →
- Part 3: Tax-Drag on Equity, Qualified Dividends, and Foreign Tax Credit →
- Part 4: Tax-Drag from Bonds →
Technical Notes and Full Assumptions
For readers who want complete transparency on how these scenarios were modeled:
- Software: Right Capital financial planning software. All cashflow, tax, and investment projections are performed by the software based on the inputs described in this post
- Base scenario: Pro-rata 70/30 allocation uniformly across all accounts. Standard withdrawal order (taxable → tax-deferred → tax-free), which is already optimal for this particular profile and is held constant across both scenarios
- Optimized scenario: Asset location strategy — equities placed in taxable first, then Roth, then 401(k); fixed income fills remaining capacity in reverse order. Same glide path, same contributions, same expenses
- Withdrawal order: Both scenarios use taxable → tax-deferred → tax-free. Held constant so the only variable between scenarios is asset location
- Mortgage: $1,400,000 balance remaining at 3% interest, ending 2050. Payments included in software cashflow
- 529 accounts: Withdrawals timed to college start dates (2034 for Child 1, 2036 for Child 2). Education costs inflated at 5% annually from today's dollars
- LTC: Not included. Retirement living expenses in the plan are assumed sufficient to cover long-term care costs if needed
- Tax rates: 35% federal, 9.3% California, 3.8% NIIT during working years. Right Capital applies appropriate tax rates in each year based on projected income
- NIIT threshold: Applied based on $600,000 income level, well above the $250,000 married filing jointly threshold
- Glide path: 70/30 today → gradual decrease → 50/50 at age 95. Applied identically in both scenarios
- All figures are in nominal dollars — not inflation-adjusted. Right Capital applies inflation to expenses based on the rates listed in assumptions
This post is for educational purposes only and does not constitute individualized investment, tax, or legal advice. The Nguyens are a fictional couple created for illustrative purposes. All scenarios are hypothetical and do not represent the experience or results of any actual individual or client of Trusted Path Wealth Management, LLC. Results were modeled in Right Capital financial planning software using the assumptions described in this post. Hypothetical expected returns are assumptions only and are not a prediction or guarantee of future investment performance. Actual results will vary based on market conditions, individual tax circumstances, legislative changes, investment selection, and many other factors. Tax rates, laws, and regulations are subject to change and may differ materially from those used in this illustration. The temporary narrowing of the gap in early retirement described in this post reflects specific modeling dynamics related to account composition and is explained in the body of the post. Tax-aware strategies are designed to be mindful of a client's tax situation but cannot guarantee specific tax outcomes. All investing involves risk, including the potential loss of principal. We do not provide tax preparation services — please consult a qualified tax professional regarding your individual circumstances before making any investment decisions. Advisory services offered through Trusted Path Wealth Management, LLC, an investment adviser registered with California.