What are Section 179 and bonus depreciation, and how are they different?

Both let you write off business equipment faster than spreading it over years, but they work differently. Section 179 lets you immediately expense the full cost of qualifying equipment — computers, machinery, furniture, certain vehicles — up to a high annual limit (over $1 million), but only up to your business income; it can't create or deepen a loss. Bonus depreciation also accelerates write-offs and can create a loss, but it's being phased down — it dropped from 100% to 80% in 2023, 60% in 2024, and continues declining unless Congress changes it. A common approach is to use Section 179 first to expense what you want, then let bonus depreciation handle the rest. Just remember: a big write-off in a low-income year may be worth less than spreading deductions into higher-income years. Coordinate timing with a tax pro.