Compliance
Compliance Essentials: Understanding PFE Rules for Energy Tax Credits Under New OBBB Safe Harbors
New guidance under OBBB introduces safe harbor rules for “Prohibited Foreign Entities” (PFEs) affecting energy tax credits—understanding MACR and PFE definitions is critical to claim these credits safely.
By NomadicTax Research Team • 5 min read • March 23, 2026
## Background: Clean Energy Tax Credits & PFEs
Under the One, Big, Beautiful Bill, eligibility for clean electricity credits under **§ 45Y & § 48E**, and the advanced manufacturing production credit under **§ 45X**, is subject to restrictions if a facility, technology, or component receives **“material assistance”** from a **Prohibited Foreign Entity (PFE)**. This is designed to ensure clean energy incentives do not indirectly subsidize entities that pose national security risks. ([irs.gov](https://www.irs.gov/newsroom/treasury-irs-provide-guidance-for-certain-energy-tax-credits-regarding-material-assistance-provided-by-prohibited-foreign-entities-under-the-one-big-beautiful-bill?utm_source=openai))
## What the New IRS Guidance Provides
Notice 2026-15 gives **interim guidance** on how to determine whether a taxpayer receives material assistance from a PFE, including:
- how to calculate the **Material Assistance Cost Ratio (MACR)**;
- examples under safe harbors provided by the OBBB to determine eligibility;
- definitions for what constitutes a PFE under the law. Some components or inputs supplied by PFEs may disqualify the credit. ([irs.gov](https://www.irs.gov/newsroom/treasury-irs-provide-guidance-for-certain-energy-tax-credits-regarding-material-assistance-provided-by-prohibited-foreign-entities-under-the-one-big-beautiful-bill?utm_source=openai))
IRS intends to publish **proposed regulations** in coming months to codify the PFE definitions and MACR rules permanently. ([irs.gov](https://www.irs.gov/newsroom/treasury-irs-provide-guidance-for-certain-energy-tax-credits-regarding-material-assistance-provided-by-prohibited-foreign-entities-under-the-one-big-beautiful-bill?utm_source=openai))
## Operational Impacts for Developers and Investors
- Before investing in renewable energy or storage projects, assess **supply chain sourcing**—if any material input comes from a PFE that cannot meet the safe harbor, it may jeopardize the credit.
- Document supplier relationships and costs meticulously. Avoid mixing PFE and non-PFE inputs without records.
- If operating under safe harbor, prepare models/classifications showing MACR calculations.
## Example: Solar Farm Development Scenario
- Solar Farm Alpha purchases panels where some cells are manufactured by a company designated a PFE. If those cells represent 15% of project cost, and safe harbor requires under, say, a threshold (e.g. <20%), Alpha must compute MACR, verify supplier is non-PFE etc.; if ratio too high, credit under § 45E may be denied.
- If components are wholly sourced from non-PFE entities, developer can rely on safe harbor treatments.
## Key Compliance Steps
1. **Engage legal and technical advisors** to map supply chains.
2. **Maintain records**—invoices, purchase orders, certifications for eligible components.
3. **Follow interim guidance now**, but expect more detailed regulations soon.
4. **File comments** by the deadline (March 30, 2026) under Notice 2026-15 if you believe certain definitions or thresholds are unclear. ([irs.gov](https://www.irs.gov/pub/irs-drop/n-26-15.pdf?utm_source=openai))
## Bottom Line
The OBBB’s PFE rules add a crucial new layer of eligibility for major energy and clean tech tax credits. By using interim guidance, safe harbors, and anticipating upcoming regulations, taxpayers can both protect their credits and avoid surprises during audits.