Where the Bonds Live
Priya and Dev Shah, both 47, hold $1,350,000 in Dev's 401(k), $310,000 in Priya's Roth IRA, $520,000 in a joint taxable account (cost basis $340,000), and $95,000 in a money market reserve. Their target is 70% stocks / 30% bonds. Today the bonds are spread proportionally across every account. The taxable account holds a total-market index fund and a REIT index fund. Their marginal rate is 32% federal plus 5% state; they expect to retire at 60 and to draw from the 401(k) at roughly a 24% federal rate. Dev argues that munis belong inside the 401(k) because they are tax-exempt, and that the 30% bond target should be measured on the balances as printed on the statements.
1. Compute the after-tax value of each account and the household's true after-tax bond exposure. Are they actually at 30% bonds?
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The statement balances are not comparable units.
| Account | Balance | Adjustment | After-tax value |
|---|---|---|---|
| 401(k) | 1,350,000 | x 0.71 (29% tax at withdrawal) | 958,500 |
| Roth | 310,000 | x 1.00, no RMD | 310,000 |
| Taxable | 520,000 | less 28.8% x 180,000 gain | 468,200 |
| Cash | 95,000 | x 1.00 | 95,000 |
| Total | 2,275,000 | 1,831,700 |
Nominal bonds of $682,500 (30% of $2,275,000) are currently held as $405,000 in the 401(k), $93,000 in the Roth, and $184,500 in taxable.
After-tax bond exposure = (405,000 x 0.71) + 93,000 + 184,500 + 95,000 cash = $660,050, or 36% of the after-tax portfolio. The 401(k) dollar is 71 cents; a bond held there bears less after-tax risk than a bond held in the Roth or taxable account, where it counts dollar for dollar. So they are somewhat more conservative than the 30% label suggests - and, more importantly, the percentages are not measuring the same thing across accounts.
If bonds are relocated entirely into the 401(k), the same $682,500 nominal produces 0.71 x 682,500 + 95,000 = $579,600, or 31.6% after tax. To hit exactly 30%, they would need about $640,000 of bonds in the 401(k) (47% of it). Either way the after-tax risk is nearly unchanged; what changes dramatically is the tax bill.
2. Where should the bonds physically sit, and what does Dev's muni idea actually cost? Quantify the alternatives.
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Location, and the size of the prize.
The after-tax allocation barely moves - the argument for location is annual tax drag, not a shift in risk. Compare the recurring cost of holding the same $184,500 of bonds in the taxable account:
- Bonds in taxable: 4.5% yield x 37% combined rate = 1.67% a year of drag, about $3,100 in year one, compounding for 25-plus years.
- Equities in taxable: 1.8% qualified dividend yield x 23.8% = 0.43% a year, plus deferral of the gain and a step-up at death.
The gap of roughly 1.2% a year on the taxable sleeve is worth several hundred thousand dollars over the horizon. Recommendation: hold $640,000-$682,500 of bonds inside the 401(k) (47%-51% of it), hold total-market equity in the taxable account, and put the REIT index in the Roth or the 401(k) - REIT dividends are largely non-qualified and the fund turns over, making it the worst possible taxable holding.
Dev's muni idea is backwards twice over. A 401(k) already shelters income, so buying a tax-exempt bond inside it trades a full taxable yield for a lower exempt yield and receives nothing in return; the plan menu likely does not offer them anyway. Munis belong only in the taxable account, and only when the tax-equivalent yield wins: at a 37% combined marginal rate, a 3.20% muni beats a taxable bond yielding more than 3.20 / (1 - 0.37) = 5.08%. Below that crossover, ordinary taxable bonds in the 401(k) and equities in taxable is the efficient answer.
3. Dev wants to execute next week. What does implementation look like without realizing a gain, and name two conditions under which this textbook answer would be wrong for them.
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Execution.
- Rebalance inside the 401(k): sell equity index, buy the bond index. No tax, no gain, done first because it is free.
- In the taxable account, redirect dividends, capital gain distributions, and all new contributions to the total-market fund. Turn off automatic reinvestment into the REIT fund.
- If more equity reduction is needed, use specific lot identification to sell the highest-basis lots first, and harvest any losses available.
- If the REIT position must go, gift the lowest-basis shares to a donor-advised fund rather than selling - full fair-market-value deduction, no gain recognized.
- Do not touch the low-basis total-market lot; it is the step-up asset.
When the textbook answer breaks:
- Step-up or charitable intent. If the taxable account will pass at death or be given to charity, the embedded gain is never taxed. The taxable account then becomes an excellent home for high-yield, high-turnover assets - bonds and REITs included - because the drag calculation collapses.
- Their future tax rate. A 29% assumption on the 401(k) drives the whole after-tax computation. If they plan conversions at 60-70, or a surviving spouse will face single brackets, the 401(k) is worth less after tax than modeled, and the optimal nominal bond position changes again.
Two secondary caveats: if the plan menu's bond fund is expensive or a stable-value fund is the only fixed-income option, the location decision is made for them; and the after-tax framework implies a nominal bond position near half the 401(k), which will look far riskier on the statement than the client expects. Agree the measurement convention in writing before trading it.