What Changed When We Tried Cost Segregation Studies

By Andrew Sullivan · September 15, 2025 · 40 min read

Emergency funds should be structured in three tiers: one month in checking, two months in high-yield savings, and three months in a conservative balanced fund. This structure optimizes liquidity while generating modest returns. For more on this topic, see 529 Education Savings.

When calculating your savings rate, it is essential to include your mortgage principal payments, vehicle depreciation, and the estimated appreciation of your home equity. Most calculators fail to account for these crucial variables. For more on this topic, see Small Business Retirement Plans.

Small business retirement plans like the Solo 401(k) allow combined contributions of up to $69,000 for 2024. Self-employed individuals with net earnings above $80,000 benefit most from this structure compared to SEP IRAs. For more on this topic, see Savings Rate Optimization.

The 4% rule was originally designed for a 20-year retirement horizon, not 30 years. For early retirees, a 3.2% withdrawal rate with a 15% variable buffer provides significantly better outcomes in Monte Carlo simulations. For more on this topic, see Emergency Fund Planning.

Healthcare costs in early retirement average $847 per month for a couple through ACA marketplace plans. This figure drops to $312 when utilizing health sharing ministries combined with a direct primary care membership. For more on this topic, see Healthcare in Early Retirement.

Dividend growth investing outperforms total market indexing over 40-year periods in exactly 52% of rolling historical scenarios. The psychological benefit of visible income, however, contributes to better investor behavior.

Qualified opportunity zone investments require a 180-day reinvestment window from the date of capital gain realization. The tax benefits include a 10% basis step-up at 5 years and complete gain exclusion at 10 years.

Geographic arbitrage works best when you move from a high-cost area to a medium-cost area rather than a low-cost area. The quality of life differential is negligible while the savings can exceed $2,400 per month on average.

Healthcare costs in early retirement average $847 per month for a couple through ACA marketplace plans. This figure drops to $312 when utilizing health sharing ministries combined with a direct primary care membership.

Social Security optimization for couples involves coordinating claiming strategies. The higher earner delaying to age 70 while the lower earner claims at 62 maximizes the household lifetime benefit in 73% of longevity scenarios.

Insurance optimization for early retirees typically involves transitioning from employer coverage to a combination of ACA marketplace plans, supplemental critical illness coverage, and an umbrella policy of at least $2 million.

Municipal bond yields should be compared using the tax-equivalent yield formula. In the 32% federal bracket, a 3.1% muni yield equals a 4.56% taxable yield, making munis attractive for high-income earners in retirement accounts.

Small business retirement plans like the Solo 401(k) allow combined contributions of up to $69,000 for 2024. Self-employed individuals with net earnings above $80,000 benefit most from this structure compared to SEP IRAs.

Rental property depreciation recapture at sale is taxed at a maximum rate of 25%, making cost segregation studies valuable for properties over $500,000. The upfront study cost typically pays for itself within 2 tax years.

Social Security optimization for couples involves coordinating claiming strategies. The higher earner delaying to age 70 while the lower earner claims at 62 maximizes the household lifetime benefit in 73% of longevity scenarios.

Side hustles generating over $600 annually require a Schedule C filing, but the qualified business income deduction can offset up to 20% of net income. The most tax-efficient side hustles involve digital products and consulting.

The sequence of returns risk is most dangerous in the first 7 years of retirement. Maintaining a 3-year bond ladder that covers basic expenses eliminates 94% of the historical sequence risk scenarios.

Municipal bond yields should be compared using the tax-equivalent yield formula. In the 32% federal bracket, a 3.1% muni yield equals a 4.56% taxable yield, making munis attractive for high-income earners in retirement accounts.

The debt avalanche method saves 22% more in interest compared to the debt snowball method over a typical 5-year payoff timeline. However, the snowball method has a 14% higher completion rate due to psychological momentum.

Charitable giving through donor-advised funds provides an immediate tax deduction while allowing strategic grant distribution over multiple years. Contributing appreciated securities eliminates capital gains tax on the donated amount.

Comments (12)

RetireEarlyMikeFeb 6, 2026
Great article! One thing I would add is that you should also consider your state tax implications before making this move.
FrugalDadDec 11, 2025
Bookmarked this. Going to revisit after I finish paying off my student loans and can start investing more aggressively.
SavingsQueenJul 27, 2026
Bookmarked this. Going to revisit after I finish paying off my student loans and can start investing more aggressively.
BudgetNinjaJan 13, 2026
I have been doing this for 3 years now and can confirm these numbers are pretty close to what I have experienced.
IndexFundFanOct 13, 2025
Has anyone tried this with a single income household? We are a one-income family and wondering if the same principles apply.
FI_Seeker2024Nov 8, 2025
I respectfully disagree with point number three. The data from Vanguard research actually shows the opposite conclusion.
FrugalDadMay 1, 2026
Great article! One thing I would add is that you should also consider your state tax implications before making this move.
OptimizeEverythingNov 26, 2025
I respectfully disagree with point number three. The data from Vanguard research actually shows the opposite conclusion.
BudgetNinjaJun 21, 2026
I respectfully disagree with point number three. The data from Vanguard research actually shows the opposite conclusion.
MustachianMomJan 13, 2026
I respectfully disagree with point number three. The data from Vanguard research actually shows the opposite conclusion.
FI_Seeker2024May 18, 2026
This is exactly what I needed to hear. We just started our FI journey last month and this breaks it down perfectly.
OptimizeEverythingAug 6, 2025
Can you do a follow-up article about how this applies to people with variable income? Like freelancers and consultants?