Every number that matters

• §6418 = transferability (sell for cash). §6417 = elective pay (direct payment; tax-exempts, governments, tribal, munis).
• Buyer: no gross income on the discount; purchase price not deductible. Seller: proceeds excluded from gross income.
• Cash only. Disguised consideration can void the election.
• Transferred once. No secondary market.
• Carryback 3 years · carryforward 22 years from the start of the carryback window = 20 years forward in practice.
• Current year first, then carryback to the earliest year. No discretion.
• Buyer takes the credit in its first tax year ending with or after the seller's tax year in which the credit was determined. ~78% of large public companies are calendar-year filers.
• Transfer happens at the partnership level; individual partners may direct sale of their own share.
• Unrelated party per §267(b) / §707(b)(1). Related-party sales prohibited.
• Progress expenditures: not transferable. Lessee in a pass-through: cannot transfer. Lessor in a sale-leaseback: can.
• Pre-filing registration: one submission per tax year, one number per property, valid for a single tax year, up to 120 days to process. Transfer election statement is irrevocable once filed by either party.

2025 §45Y (factor 1.9971): $6 base / $30 PWA per MWh. 2026 §45 (factor 2.0570): $30/MWh PWA for wind, closed-loop biomass, geothermal, solar; $15/MWh for open-loop biomass, landfill gas, trash. Base rounds to nearest $0.50; the $15 PWA rate rounds to nearest $1.

ITC stacking

• Base 6% → PWA 30% → + energy community 40% → + domestic content 50%.
• Without PWA each adder is only 2 points (so 6 + 2 + 2 = 10%).
• Low-income is separate: 10% (categories 1–2) or 20% (categories 3–4), allocated and capped, <5 MWac.

PTC stacking

Adders are a 10% increase in value, not percentage points. $30/MWh → $33 with energy community → $36/MWh with both adders.

§50 recapture (ITC only)

Five years from PIS: 100 / 80 / 60 / 40 / 20%, clean in year six. Triggers: destroyed & not rebuilt, abandoned, ceases selling electricity from the qualified asset, change in ownership (including lender foreclosure). Exception: upstream partnership/S-corp ownership change triggers recapture to the selling partner, not the credit buyer. PTCs have no recapture.

FEOC recapture (§48E): 10 years, 100%, no step-down, for applicable payments to an SFE giving effective control. Tax years beginning after 7/4/2027; facilities placed in service 2028+.

Phase-downs

• Wind & solar (§45Y/§48E): BoC before 7/5/2026 + PIS within 4 years of the BoC tax year; OR BoC after 7/4/2026 + PIS before 1/1/2028.
• All other tech: BoC before 1/1/2036, PIS within 4 years. 2034 → 75%; 2035 → 50%.
• §45X: wind components sold before 1/1/2028 (no taper). Critical minerals before 1/1/2034 (75/50/25% in 2031/32/33). All others before 1/1/2033 (75/50/25% in 2030/31/32).
• §45 wind phaseout (PIS before 1/1/2022, by BoC year): pre-2017 100% · 2017 80% · 2018 60% · 2019 40% · 2020–21 back up to 60%.

• Multiplier: ×5. Applies to taxpayer, contractors and subcontractors.
• Rates from SAM.gov, locked at contract execution; reset on substantial scope additions or term extensions; annual update for open-ended alteration/repair contracts. Offshore wind uses the closest onshore location.
• Basic maintenance exempt — routinely scheduled, continuous or recurring (inspections, cleaning, filters, bulbs, calibration).
• Start-of-work definition for PW is 29 CFR 5.2 (Davis-Bacon) — broader than the IRS BoC test. Demolition can require PW without starting construction for tax purposes.

Apprenticeship — all three required

• Labor hours: 12.5% (BoC in calendar 2023) · 15% (BoC after 12/31/2023). Supervisors excluded unless >20% of the workweek is manual labor.
• Ratio: apprentice-to-journeyworker per the registered program, met daily.
• Participation: 4+ mechanics/laborers → must employ 1+ qualified apprentice.
• Apprenticeship requirements stop at placement in service. Post-PIS compliance is prevailing wage only.

Duration by credit

Exemptions

• BoC before 1/29/2023 — except §48C and §45Z, which never get it.
• <1 MWac max net output (§45/§48/§45Y/§48E). Thermal equivalent 3.4 mmBTU/hr; hydrogen/biogas 10,500 scf/hr. Electrochromic glass, fiber-optic solar and microgrid controllers do not qualify.

Cures and penalties

• Cure window: 180 days from the IRS final determination (not the violation).
• Back wages ×3 for intentional disregard, + interest at §6621 short-term + 6%.
• Penalty $5,000 per worker per calendar year ($10,000 intentional).
• Penalty waiver: corrective payment by the last day of the first month after the quarter, AND either underpaid ≤10% of pay periods OR shortfall ≤5% of what was owed. Also waived under a QPLA (six requirements, 26 CFR §1.45-7(c)(6)(ii)).
• Apprentice hours shortfall cure: $50/hr ($500 intentional). Good faith effort: request denied or 5 business days of silence; valid 365 days.
• §48 sellers file an annual prevailing wage compliance report throughout the 5-year recapture period.

Energy community — three paths

• Brownfield — presence or potential presence of hazardous substance/pollutant/contaminant; certain mine-scarred land.
• FFE / statistical area — (a) ≥0.17% direct fossil employment OR ≥25% local tax revenue, and (b) unemployment ≥ national average for the prior year.
• Coal census tract — tract or directly adjoining tract with a mine closed after 1999 or a coal generating unit retired after 2009.
• Lock-in: BoC on/after 1/1/2023 in a qualifying location keeps EC status for the 10-yr credit period or as of PIS. FFE list changes annually (usually May); coal tract list is stable. Latest: Notice 2025-31 (6/23/2025).

Domestic content

• Steel & iron: 100% US-produced (except metallurgical refinement of steel additives).
• Manufactured products adjusted %: before 6/16/2025 40% · 6/16–12/31/2025 45% · 2026 50% · after 12/31/2026 55%. Offshore wind starts at 20%.
• Adjusted Percentage Rule uses the manufacturer's direct labor and materials, not sales price. Installation labor excluded.
• Elective safe harbor (Notice 2024-41, modified by 2025-08): fixed IRS percentages instead of supplier cost data. All-or-nothing for the whole project. Unlisted components are excluded, not disqualifying. Certification filed with Form 8835 (PTC) or 3468 (ITC) in the first year claimed.

Low-income community (2026)

• All projects <5 MWac. Apply via DOE; IRS allocates. Applications in the first 30 days are simultaneous; oversubscribed categories are randomized.
• 50% reserved for ownership/geographic criteria. Persistent poverty county = 20% poverty over 30 years.
• 4 years to PIS, no extensions, no location change, no PIS before allocation. DOE info requests: 12 business days.
• Oversized (but <5 MWac): pro-rata reduction factor. Undersized by more than the greater of 2 kW or 25%: disqualification. Ownership change before PIS where allocation relied on ownership criteria: disqualification.
• 2025+ program years run under §48E(h) (Rev. Proc. 2025-11); §48(e) applies only to 2023–24.

Two regimes: taxpayer-level (who you are) and material assistance (what's in your project). PFE = SFE + FIE.

Taxpayer-level

• Six credits: §45Y, §48E, §45X, §45Q, §45U, §45Z. For the first four, SFE and FIE prohibitions start with the tax year beginning after 7/4/2025. For §45U and §45Z, the FIE prohibition starts after 7/4/2027.
• Covered Nations: China, Russia, North Korea, Iran. FCE = 50%+ owned by a Covered Nation government/agency/national or a company based there.
• Named SFEs: CATL, BYD, Envision Energy, EVE Energy, Gotion High Tech, Hithium (+ successors).
• FIE triggers (any one): SFE can appoint a covered officer · 25% single-SFE ownership · 40% multiple-SFE aggregate · 15% of debt held by an SFE · effective control.
• Effective control / licensing: automatic violation if you enter into or modify a license with an SFE post-enactment. Otherwise: no royalties >10 years, no required services agreement >2 years. IP sale with a reversion is not bona fide.
• Cannot transfer §48E/§45Y/§45X/§45Q/§45U/§45Z credits to an SFE — so diligence the buyer.
• Testing dates (2026 calendar filer): SFE on 1/1/2026; FCE and FIE on 12/31/2026.

Material assistance cost ratio (MACR)

MACR = (Total Direct Costs − PFE Direct Costs) / Total Direct Costs. Three credits only: §45Y, §45X, §48E. Exempt if BoC before 1/1/2026 — using Notices 2013-29 / 2018-59 as in effect 1/1/2025. Guidance: Notice 2026-15 (2/12/2026), interim.

Safe harbors: Identification, Cost Percentage (only with Identification; all-or-nothing once elected), Certification (supplier certs, unless you know or should know they're invalid), De Minimis (<10% of total direct costs), and averaging for storage <1 MWac. QIP needs its own separate MACR; Identification and Cost Percentage unavailable for it.

BoC determines: credit/bonus eligibility · PWA exemption · FEOC exemption.

• Physical work of a significant nature + Continuous Construction. On-site excludes planning/design, permits, surveys, studies, test drilling, site clearing, and excavation to recontour land — but includes excavation for footings and foundations, setting anchor bolts, pouring concrete pads. Off-site requires a binding written contract and components not in inventory (custom transformer is the classic).
• 5% Safe Harbor + Continuous Efforts. Only costs in depreciable basis; excludes land and non-integral property.
• Continuity Safe Harbor: PIS by end of a calendar year no more than 4 years after the BoC year. Notice 2021-41 gave 6 years for 2016–2019 BoC and 5 for 2020.
• Notice 2025-42 (8/15/2025, per EO 14315): all wind + solar >1.5 MW must perform physical work — no 5% safe harbor. Old rules preserved for projects establishing BoC before 9/2/2025, and for solar ≤1.5 MW (measured at each inverter, aggregated if same taxpayer + same year + same interconnection point). Applies only to wind/solar under §45Y and §48E.
• Live issue: on 6/6/2026, Oregon Environmental Council v. IRS (D.D.C.) vacated Notice 2025-42 in full. Appeal expected. Verify the current state before relying on either regime.

• Premium §45 PTC = creditworthy seller and volume ≥$25M. IG sponsors get a ½–1¢ premium on PTCs, 1–2¢ on ITCs.
• Discount widens with: cost basis step-ups, weak credit support, immature technology, size below $5–10M, residential solar portfolios, and forward/multi-year commitments.
• ITCs sold in Q1/Q2 trade lower — buyers won't pre-pay relative to their IRS payment dates.
• §45X opened Dec 2023 at $0.87–0.96; has since converged on §45 pricing.
• Keystone: corporates may offset quarterly estimated tax payments with credits they intend to purchase — enabling zero-out-of-pocket structures (quarterly in arrears, or commit early / pay late).

• Excessive credit transfer: buyer liable for the excess + 20% penalty. Reasonable cause can waive the penalty only — key factor is the buyer's efforts (records review, third-party expert reports, seller reps).
• Indemnity covers loss/reduction/recapture/disallowance + interest and penalties; excludes the buyer's own failure to claim and the buyer's lack of tax liability. Include a tax gross-up. No-fault beats breach-based.
• Transferor = the first regarded entity owning the project (usually the partnership above a disregarded project LLC). Guarantee sizing: 5-yr recapture step-down + ~3-yr audit statute.
• Tax credit insurance: $0.03–0.05 per $1.00 (up from $0.02–0.03 in 2024/early 2025). Hard below $3–5M volume. Pays first, indemnity backstops. Excludes prospective tax law changes, inconsistent filing positions, unconsented settlements, and insured-caused recapture.
• Recapture mitigation: forbearance agreements with lenders (negotiated when debt is raised), P&C insurance, site control, interconnection rights, offtaker alternatives.
• CAMT: 15% of AFSI; thresholds $1B (US parent) / $100M (US sub of foreign multinational with $1B+); interim simplified method uses $800M / $80M. General business credits do not reduce AFSI — a hard cap on how many credits a CAMT-exposed buyer can use.