The 30C credit after its sunset: what a model still does with it

For most of the last decade, the federal 30C credit — the Alternative Fuel Vehicle Refueling Property Credit — was the largest single incentive in a charging-site pro forma. Under the One Big Beautiful Bill Act, signed July 2025, it terminated for property placed in service after June 30, 2026.

That date has passed. A model built today has to handle three different situations, and only one of them is "the credit is gone."

What the credit was#

For business property in an eligible census tract, 30C was worth 30% of qualified cost, capped at $100,000 per port, where the full 30% rate required meeting prevailing wage and apprenticeship conditions during construction. Projects that missed those conditions fell to a base rate a fraction of that size.

On an eight-stall site at the model's default cost, the credit at the full rate was worth several hundred thousand dollars — routinely the difference between a marginal site and a comfortable one. Its removal is the single largest change to US charging-site economics in this program's history, and any pro forma or template still carrying a 30C line for a new build is overstating returns by roughly that amount.

Three situations#

Placed in service on or before June 30, 2026. The credit may still be claimed on a timely filed return, or on an amended return if it was missed. Eligibility turns on the placed-in-service date, not the date of purchase, contract, or construction start — so a site energized in June 2026 qualifies even if most of its spending happened later than a site energized in July that does not.

Placed in service after June 30, 2026. No credit. The model returns NO — sunset for these dates and carries a credit value of zero. There is no partial-year proration and no transition rule that revives it.

In construction now. The credit is unavailable regardless of when the project started, which changes what a project needs to clear on its own merits. Sites underwritten in 2024 and 2025 on a post-credit basis are carrying an assumption that no longer holds, and the gap is not small.

The rule that outlives the credit#

There is one piece of 30C that matters after the sunset for anyone who claimed it: IRC §50(c)(3) basis reduction.

When the credit was claimed, the depreciable basis of the property had to be reduced by half the credit amount. The credit was cash in year one; the basis reduction is a smaller depreciation deduction in every year after.

That means a site that claimed 30C carries a permanently higher taxable income than its purchase price alone would suggest, for the whole depreciation schedule. A model that books the credit and skips the basis adjustment overstates after-tax cash flow for fifteen years — an error that compounds quietly, in the opposite direction and on a longer timescale than the benefit it accompanies.

The engine applies the reduction automatically whenever the credit is eligible, carrying the adjusted basis into the depreciation and tax modules rather than the original. Where a grant also reduces basis, both reductions apply in sequence.

What remains#

The federal credit's removal does not empty the incentive stack; it changes its shape from federal-and-broad to state-and-conditional.

• NEVI remains the largest source of outside capital, with an FY2026 apportionment of $885 million routed through state solicitations. It is competitive, deadline-bound, and carries its own basis and prevailing-wage consequences — covered in NEVI funding for a privately owned site.
• State grants and utility make-ready programs vary widely and change quickly. The incentives checker records what is currently filed for each jurisdiction, with unverified entries flagged rather than guessed.
• Clean-fuel credits are ongoing revenue rather than capital support, and exist in only four states in the library — see LCFS credits, net of commission.

The structural difference is that 30C was a capital subsidy available almost everywhere on the same terms. What replaces it is a patchwork where the answer depends on the state, the round, and the calendar. That makes location a larger determinant of outcome than it was, on top of a utility tariff that already varies by a factor of about 8.5 across the filed library.

The methodology page lists the statutory sources and their effective dates, and the scenario wizard applies the sunset rule from a scenario's own placed-in-service date.

This is a description of how the model treats a tax provision, not tax advice. Eligibility, census-tract designations, wage and apprenticeship conditions, and amended-return options are fact-specific — a qualified tax advisor should determine what applies to any particular project.