California does not conform to federal §168(k) bonus depreciation in 2026. Short-term rental investors who acquire qualifying property this year still receive the full federal Year-1 deduction — 100% of bonus-eligible 5-year and 15-year property — but must add that deduction back on their California state return and depreciate normally over the asset's class life for state tax purposes. The federal cash savings are unaffected. State-level savings are reduced or deferred.
This article is for STR investors who already understand the federal mechanics — the One Big Beautiful Bill Act restored 100% bonus depreciation permanently — and need to know how California's non-conformity changes the math. We cover what it means for CA-based investors, what it means for out-of-state buyers acquiring California property, the workaround at the federal level, and the worked-example numbers a CPA needs to size the strategy.
What California Non-Conformity Actually Means
California decoupled from federal bonus depreciation in 2002 and has not reconnected since — including in 2026. The Franchise Tax Board (FTB) requires taxpayers to add back any federal §168(k) bonus depreciation on Schedule CA (540) and depreciate the same property over its normal MACRS class life for state tax purposes.
The mechanics in plain English: at the federal level you claim 100% of bonus-eligible components in Year 1. At the state level you pretend §168(k) does not exist — the property gets standard 5-year, 15-year, or 27.5/39-year depreciation. The Year 1 state deduction is much smaller. Over the property's life, total state deductions equal what you would have claimed under bonus depreciation; only the timing is different.
This is not a loophole closure or a recent policy change. It is a long-standing structural feature of California tax law that applies equally to other accelerated federal provisions (§179 expensing limits also differ, for example). The strategy still works; the size of the state-level benefit just looks different on the return.
What This Means for California-Based STR Investors
If you are a California resident buying a short-term rental — whether the property is in California, Tennessee, or anywhere else — you pay California tax on your worldwide income. The state add-back applies regardless of where the property sits, because the rule attaches to where you file, not where the property is located.
The strategy still produces material cash savings. Consider a California physician at the top federal bracket (37%) with a $200,000 Year-1 federal bonus deduction. Federal tax savings: roughly $74,000. California's top marginal rate is 12.3% (13.3% with the mental health surcharge above $1M income). The state add-back means you do not get the full $200,000 deduction on your CA return — only the first-year MACRS schedule amount, which for a typical mix of 5-year and 15-year property would be in the $25,000–$40,000 range.
Over the property's life, the deferred state deductions catch up. Year 1 is smaller; Years 2–15 are larger than they would otherwise be (because federal bonus already consumed Year 1 federally, but state still has the asset basis intact). The state-level benefit is the same in total — California has not eliminated the deduction, just delayed it.
What This Means for Out-of-State Investors Buying California STR Property
The picture is different if you live in Texas, Tennessee, Florida, or another conforming state and acquire a California short-term rental. You will likely owe California non-resident state income tax on the rental income (and any gain on sale), but your federal return is straightforward: 100% bonus depreciation applies at the federal level just as it would on an STR in any state.
For state tax purposes, you file a California non-resident return (Form 540NR) reporting the California-source rental income. The same add-back rule applies on that return: federal bonus depreciation must be reversed for the California calculation. But because your overall California tax exposure is limited to the California-source income, the dollar impact of the add-back is proportionally smaller.
Practical implication: Out-of-state investors in conforming states (TX, TN, FL, NV, AZ, etc.) buying California STRs capture nearly all of the federal benefit and absorb a small additional state-level cost on California-source income. The math frequently still favors the deal, especially in high-tax-bracket scenarios.
Does Cost Segregation Still Work in California?
Yes — and it remains the right move on any STR over roughly $400,000–$500,000 in purchase price, in any state including California. A cost segregation study (or a calibrated AI engineered estimate) identifies which property components are 5-year personal property, 15-year land improvements, or 39-year structural property. That classification work is federally valuable regardless of state conformity.
Here is why: at the federal level, the 5-year and 15-year components qualify for 100% bonus depreciation under §168(k). Without a cost seg study you cannot defensibly identify those components, which means the entire purchase price gets allocated to 27.5- or 39-year residential property and deducted at roughly 3.6% per year. The cost seg unlocks the bonus eligible basis.
For California state purposes, the same components are still depreciated — just over their normal class lives. The cost segregation does not change the state outcome materially compared to no-cost-seg; the same allocation rules apply. So the marginal value of cost segregation is the federal Year-1 deduction. On a California STR at $850,000 with 20% bonus eligible, that is $170,000 of Year-1 federal deduction — roughly $63,000 in federal cash savings at the top bracket. The cost seg study (or DepreciMax engineered estimate at $99) pays for itself many times over even with California's non-conformity.
For a fuller breakdown of how the two interact, see cost segregation vs. bonus depreciation.
Worked Example: $950,000 Joshua Tree STR for a California Resident
The federal side carries the trade: $77,330 in Year-1 cash savings on a $209,000 §168(k) deduction. California adds roughly $4,059 — California rejects §168(k) so the state deduction is just the standard MACRS first-year amount on the same 5-yr and 15-yr property (~$33,000), taxed at the 12.3% top bracket. Total Year-1 federal-plus-state cash benefit: ~$81,389.
Over the property's life, California state deductions still equal the same total dollars (Years 2–15 absorb the deferred amount), so the cumulative state benefit is preserved — just spread out instead of concentrated.
Compare this to a Texas resident buying the same Joshua Tree property: same $77,330 in federal benefit, plus a California non-resident return reporting only the property's California-source income (small relative to federal earnings). The Texas resident captures essentially the same federal Year-1 benefit with negligible incremental state cost.
Run the numbers on your California STR
Upload 7–9 listing photos. Get a line-item bonus depreciation estimate closely calibrated to a formal $5,000–$12,000 cost seg study — in minutes, before you make the offer.
Run a Property Report — $99 →The Other Non-Conforming States to Know About
California is the most common non-conforming state for STR investors because of its size and the popularity of California desert and coastal markets. But it is not the only one. As of 2026, the following states have not conformed to federal §168(k):
- California — full add-back, recovery over MACRS class life
- New York — full add-back, similar mechanics to CA
- New Jersey — full add-back; gross income tax does not allow bonus dep
- Massachusetts — full add-back on personal income tax returns
- Illinois — partial conformity; check current year for percentages
- Hawaii — full add-back; investors face both non-conformity and high overall tax burden
- Pennsylvania — full add-back on personal income tax
States that fully conform — meaning bonus depreciation flows through to the state return identically to the federal — include Florida, Texas, Tennessee, Nevada, Wyoming (no income tax in any of those), and most other states with income tax including Arizona, Colorado, Georgia, North Carolina, Utah, and many more. The state conformity rule is the single biggest variable in calculating total tax savings on an STR strategy. Our 2026 STR Bonus Depreciation Market Study includes the full state §168(k) conformity map alongside 197 US STR market rankings so you can see conformity and bonus-eligible potential in one view.
The Bottom Line for California STR Investors in 2026
California non-conformity to bonus depreciation is real and material, but it does not kill the strategy. The federal Year-1 deduction is the largest piece of the savings — typically $50,000–$120,000 in cash for a California-bracket high earner on a single STR — and that benefit is fully available. The state add-back delays but does not eliminate the California-level benefit; the same total deduction is claimed over the property's life, just on a normal MACRS schedule instead of compressed into Year 1.
The right move is still to run a cost segregation analysis (or a $99 DepreciMax engineered estimate as a pre-purchase screen) on any California STR you are considering. The federal Year-1 dollars more than justify it, and the state-level math is no worse with a study than without one.
Frequently Asked Questions
Does California conform to bonus depreciation in 2026?
No. California has not conformed to federal §168(k) bonus depreciation. STR investors who acquire qualifying property in 2026 receive the full federal Year-1 deduction but must add the bonus depreciation amount back on their California state return and depreciate the property on the standard California schedule. The federal savings are unaffected; only state-level savings are reduced.
Can I use cost segregation on a California short-term rental in 2026?
Yes. A cost segregation study (or a calibrated AI engineered estimate) is still federally valuable on California STRs because §168(k) bonus depreciation applies in full at the federal level. The 5-year and 15-year property identified by the study unlocks 100% Year-1 federal deduction. For state purposes, the same components must be depreciated normally — but the engineering work to identify them is the same.
Is California STR bonus depreciation worth claiming if the state requires an add-back?
In most cases yes. The federal Year-1 deduction at a 37% bracket on $150,000–$300,000 of bonus-eligible property is $55,000–$110,000 in cash federal savings. California's top marginal rate of 12.3% applied to that same amount would have been $18,000–$37,000 in additional state savings — meaningful, but the federal benefit alone justifies the strategy. The state add-back recaptures timing, not the deduction itself; over the property's life, total deductions are the same on both returns.
What is the difference between bonus depreciation and cost segregation in California?
Cost segregation is the engineering analysis that identifies which property components are 5-year personal property, 15-year land improvements, or 39-year structural property. Bonus depreciation under §168(k) is the federal tax election that lets you deduct 100% of the 5-year and 15-year components in Year 1. California accepts the cost segregation classifications but rejects the §168(k) election — components are depreciated over their normal class lives for state tax purposes. Both still apply federally.