Cost Segregation Study in South Carolina

South Carolina is a decoupling state that gives back most of what it takes. It does not allow bonus depreciation, but it conforms fully to Section 179, which for a cost segregation study is often the more useful of the two. It excludes 44% of net long-term capital gains, which drops the effective rate on a property sale to roughly 3.5%. And its pass-through entity tax rate of 3% is among the lowest in the country.

The result is a state where the right answer depends heavily on which federal elections you make and how much South Carolina business income you have to absorb them.

How South Carolina Income Tax Interacts With Federal Strategy

South Carolina's individual income tax has been stepping down under the 2022 income tax reform. The top marginal rate reached 6.2% for tax year 2025, with statutory triggers that reduce it further toward 6% when general fund revenue growth targets are met.

South Carolina allows a deduction equal to 44% of net capital gain held more than one year. That exclusion brings the effective top rate on qualifying long-term capital gain to roughly 3.47%, which is meaningfully lower than the ordinary rate and materially changes exit planning.

The exclusion applies to net capital gain. Section 1245 depreciation recapture is ordinary income and does not qualify. Unrecaptured Section 1250 gain is capital gain and does qualify. That distinction is central to the South Carolina cost segregation analysis and is covered below.

South Carolina conforms to the federal passive activity loss rules of IRC Sec. 469.

South Carolina Pass-Through Entity Tax

South Carolina enacted its elective pass-through entity tax in 2021 under South Carolina Code Section 12-6-545(G). The election is annual and made on the entity return.

The rate is 3%, tied to the state's active trade or business income rate rather than the top individual rate. That makes South Carolina's PTET one of the lowest-rate elections available anywhere, and it produces an unusual result: for active business income, the entity-level election is not just a federal deduction strategy, it is also a state rate reduction from 6.2% down to 3%.

Members receive a South Carolina credit for their share of the tax paid. Because the electing entity pays at 3% rather than the member's marginal rate, the arithmetic here is more favorable than in states where the PTET rate simply matches the top individual rate.

The election requires care around what qualifies as active trade or business income versus passive investment income, since rental activity does not automatically qualify. This is a place to get advice specific to your structure rather than to assume the 3% rate applies to everything the entity earns.

South Carolina Depreciation Conformity

South Carolina adopts the Internal Revenue Code as of a fixed conformity date but specifically does not adopt bonus depreciation under IRC Sec. 168(k). Federal bonus depreciation is added back and South Carolina depreciation is recomputed on MACRS without bonus.

South Carolina does conform to Section 179 at full federal limits. That conformity is unusually valuable in a cost segregation context, because Section 179 is the one remaining path to immediate South Carolina expensing on the short-life personal property a study identifies.

The practical implication is that the federal election you make on the reclassified property drives the South Carolina outcome. Take 100% bonus on a $600,000 reclassification and South Carolina gives you MACRS only. Elect Section 179 on the qualifying portion and South Carolina gives you the full deduction in year one on that portion.

Section 179 will not cover everything a study finds. It does not apply to fifteen-year land improvements, it cannot create or increase a net loss, and it is subject to the business taxable income limitation. But on the five and seven-year personal property that typically makes up the bulk of a study's reclassification, it is available.

Cost Segregation Considerations Specific to South Carolina

Four items drive the South Carolina analysis.

First, run the Section 179 election as a deliberate line-item decision on the study output. This is the single highest-leverage choice in South Carolina. Identify which reclassified assets qualify for Section 179, confirm you have enough South Carolina business taxable income to absorb the election, and then decide asset class by asset class rather than defaulting to bonus on everything.

Second, understand what the study does to the 44% exclusion on exit. A cost segregation study converts Section 1250 real property into Section 1245 personal property. Section 1250 unrecaptured gain qualifies for the 44% South Carolina exclusion and is effectively taxed near 3.47%. Section 1245 recapture is ordinary income taxed at the full 6.2%. So the study raises the South Carolina rate on the reclassified portion at disposition by roughly 2.7 percentage points.

Third, weigh that exit cost against the acceleration. On a $600,000 reclassification, the additional South Carolina tax at sale is roughly $16,000 relative to the Section 1250 treatment. Against a federal deduction worth up to $222,000 in year one, the trade is clearly favorable, and a 1031 exchange or a hold to death eliminates the exit cost entirely. But it should appear in the model rather than being discovered at closing.

Fourth, maintain the South Carolina schedule. Because South Carolina disallows bonus, South Carolina basis exceeds federal basis for the life of the asset and South Carolina gain on sale is smaller than federal gain. If you elected Section 179 on part of the reclassification, that portion has matching basis and the rest does not, which makes the schedule more complex than in a state that simply disallows everything.

Working With AE Tax Advisors in South Carolina

AE Tax Advisors works with real estate investors, business owners, and high-income professionals across South Carolina and all fifty states. We are a licensed CPA and IRS Enrolled Agent practice based in Billings, Montana, and we handle the engineering-based cost segregation study, the Section 179 versus bonus election analysis, the pass-through entity election, and the return preparation as one engagement.

South Carolina is a state where the study report and the tax return have to be prepared by people talking to each other. The federal election choice on the reclassified property is nearly irrelevant federally and decisive for South Carolina, and a provider who hands you a report and walks away cannot make that call for you.

Related reading: the complete guide to cost segregation, our cost segregation study service, short-term versus long-term rental tax treatment, lookback studies and Form 3115, and multi-state tax planning.

South Carolina tax rates, pass-through entity tax rules, and depreciation conformity provisions described on this page reflect law in effect as of August 2026 and are provided for general information only. State conformity changes frequently and often retroactively. Nothing here is tax advice for your situation, and no client relationship is created by reading it. Talk to us about your facts before acting.