State-by-State Bonus Depreciation: Which States Don't Conform to Federal Rules?

Federal bonus depreciation creates enormous first-year deductions for STR investors. But many investors are surprised to discover that their state income tax return tells a completely different story. A majority of states do not fully conform to federal bonus depreciation rules — some cap it, some disallow it entirely, and some require you to add back the federal deduction and depreciate on your state return according to a different schedule. Understanding your state's treatment is essential for accurate tax planning.

Why States Decouple from Federal Bonus Depreciation

States rely on income tax revenue to fund their budgets. Federal bonus depreciation dramatically reduces current-year taxable income — which directly reduces state income tax receipts. States that conform to federal bonus depreciation take a short-term revenue hit (which they recoup over time as depreciation carryforwards are used). Many states decided this short-term hit was unacceptable and opted to decouple from federal bonus depreciation, requiring taxpayers to compute a separate state depreciation schedule.

State Conformity Categories

How Decoupling Works in Practice

In a decoupled state, you file two separate depreciation schedules: one for your federal return (with 100% bonus depreciation) and one for your state return (with regular MACRS depreciation). The state requires you to add back the federal bonus depreciation claimed, then deduct only the MACRS depreciation amount allowed under state rules.

Example: Maria buys an Airbnb in New Jersey. On her federal return, she claims $120,000 in year-one bonus depreciation on reclassified assets. On her NJ state return, she adds back $120,000 and can deduct only the regular MACRS depreciation — approximately $24,000 in year one (first-year 200% DB deduction on 5-year property). Her NJ taxable income is $96,000 higher than her federal taxable income.

The State Add-Back Creates a Timing Difference

When your state decouples from federal bonus depreciation, you don't lose the deductions — you defer them. The assets continue to depreciate on your state return according to the regular MACRS schedule over their remaining recovery period. Eventually, you'll have claimed the full basis on your state return — it just takes longer.

This creates a temporary difference between your federal and state depreciation schedules that requires careful tracking. Many STR investors in decoupled states end up with a state depreciation carryforward that builds up over the years and gradually offsets future state income.

California: A Specific Case Study

California is the most significant decoupled state due to both its large population of STR investors and its 13.3% top marginal income tax rate. California does not conform to federal bonus depreciation under §168(k) at all. STR investors in California must compute separate California depreciation using pre-TCJA rules.

Despite the state limitation, California STR investors still receive the full federal benefit — and at a 37% federal + 9.3–13.3% California combined rate, the total marginal rate can exceed 50%. The federal bonus depreciation deduction alone saves a California high-earner 37 cents per dollar of deduction, even without the state benefit.

What to Do If Your State Decouples

1. Use tax software or a CPA that handles state depreciation tracking. You need separate depreciation schedules for federal and state — this cannot be done accurately with a single schedule.
2. Don't reduce your federal bonus depreciation election because of state taxes. The federal savings are substantial even in high-tax states. Opting out of bonus depreciation to simplify state compliance is usually a costly mistake.
3. Understand your state's specific add-back rules. Some states require a specific add-back form; others require a modification on the state return. The exact mechanics vary by state.
4. Track the state depreciation carryforward. The deductions you can't take currently on your state return accumulate and will offset future state income — understand when and how they'll be recovered.