Fannie Mae & Freddie Mac Changed Radon Testing Rules in March 2025: What Multifamily Owners Need to Know

1. What changed and when

On March 26, 2025, the Federal Housing Finance Agency (FHFA) announced that it was rescinding its 2022 directive that had standardized radon testing requirements across Fannie Mae and Freddie Mac multifamily loans. The downstream effect was immediate. Both agencies updated their environmental forms, and the post-rescission rules are what apply today.

The shorthand: each enterprise still sets its own radon requirements through its current multifamily guide, but the uniform federal mandate is gone and the environmental consultant's judgment now carries more weight in deciding whether testing is warranted on a given property. The specific testing scope comes from the current Fannie Mae or Freddie Mac guide that the lender uses. Federal standardization is out. Consultant judgment is in.

HUD MAP Guide rules, which govern FHA-insured multifamily loans, were not affected by the FHFA action. HUD testing remains binding at the prior levels.

2. What the 2022 directive said

The 2022 FHFA directive standardized radon testing across both agencies. It prescribed testing based on factors like the property's radon zone and the size of the building, applied through each enterprise's environmental forms. The effect was a single, uniform expectation across Fannie Mae and Freddie Mac.

Under the 2022 rules:

• A minimum share of ground-contact units had to be tested on most agency-financed acquisitions.
• EPA Zone 3 properties (lowest predicted radon) had previously been optional. The 2022 directive made testing mandatory across all zones.
• Reports had to be signed by a qualified measurement professional under each agency's definitions.
• Mitigation, when required, had to follow recognized commercial-building protocols.

The 2022 directive made multifamily radon testing far more common than it had been historically and pushed many regional firms and environmental consultants to build in-house radon capacity. The whole market scaled up to meet the rule.

3. What Fannie Mae now requires

Fannie Mae continues to set its own radon testing requirements through its current multifamily guide, but gives the environmental professional more room to determine whether testing is warranted on a given property, considering property type, geology, radon zone, and applicable state or local law. The controlling requirement for any specific loan is whatever Fannie Mae's current guide specifies, so confirm it with your lender.

In practice this means:

• Where the consultant determines testing is warranted, Fannie Mae's current guide sets the testing parameters.
• An environmental consultant can decline to recommend testing on a property in a low-radon zone with no other risk indicators.
• An environmental consultant in a higher-zone property (most of north Georgia, for example) will typically still recommend testing because the predicted risk is high enough that not testing creates real exposure.
• Lender credit policies sometimes still require testing even when Fannie Mae does not. That is a deal-level discussion with the originator.

4. What Freddie Mac now requires

Freddie Mac also continues to require radon testing when the environmental consultant determines it is warranted. The specific sampling coverage is set by Freddie Mac's current multifamily standard, and the consultant's professional judgment now drives whether testing is triggered on a given property. As with Fannie Mae, the controlling requirement is whatever Freddie Mac's current guide specifies for the loan, so confirm it with your lender.

The decision tree at Freddie Mac now looks like this:

• The environmental consultant evaluates the property and decides whether testing is warranted.
• If the consultant says testing is warranted, the sampling coverage follows Freddie Mac's current standard.
• If the consultant says testing is not warranted, no testing is required at the agency level.
• The qualified measurement professional requirement for signing reports was retained.

The practical effect is that Freddie Mac still requires meaningful testing coverage when a consultant determines it is warranted, but consultants now have more room to scope the decision to the property's actual risk.

5. What HUD MAP Guide still requires

The FHFA action did not touch HUD. The HUD MAP Guide, which governs FHA-insured multifamily loans, retains the testing requirements that were in place before the 2022 directive and remain in place after the rescission:

• Testing covers ground-contact units plus a sample of upper-floor units, following HUD's current standards.
• Confirm the exact sampling that applies to your loan with your lender, since HUD has updated these requirements over time.
• Reports must be signed by a qualified measurement professional under HUD's specific definition.
• Mitigation, when required, must follow recognized commercial-building standards.

For affordable properties, Section 8 acquisitions, Section 232 senior living, RAD conversions, and any other FHA-insured deal, the HUD rules are the binding rules. Fannie Mae's and Freddie Mac's changes do not apply.

6. Why environmental consultants now control the call

The 2022 directive moved much of the decision out of the consultant's hands and into a uniform federal matrix. The rescission gave the consultant's judgment a larger role again, even though each enterprise kept its own requirements. That has a few practical consequences.

First, consistency varies. Two environmental firms looking at the same property may reach different conclusions about whether testing is warranted. The factors most consultants weigh today include EPA radon zone, building age and slab construction, prior testing history in the surrounding submarket, and any state or local guidance.

Second, documentation matters more. A consultant's written rationale for either recommending or declining radon testing is now a meaningful piece of the deal file. If a buyer or lender wants to push back on the recommendation, the written justification is what the conversation happens against.

Third, post-close exposure shifted. Under the old directive, a buyer could point to the standardized rule and say the testing was required. Under the new approach, if a consultant declined testing and a problem surfaces later, the framing becomes whether the consultant exercised reasonable professional judgment given what was knowable at the time.

7. What it means for in-flight and refi deals

Deals that closed under the 2022 directive used the rules in force at the time. There is no retroactive obligation. Deals in process during March 2025 generally followed whichever form was in effect at the time the consultant scoped the Phase I.

For acquisitions opening in 2026, the new approach is the operating reality:

8. Why Georgia properties still get tested

Georgia is a higher-radon state in aggregate. The EPA radon-zone map ranks counties by predicted indoor radon. Several north Georgia counties carry Zone 1 designations (predicted average above 4.0 pCi/L), and most of metro Atlanta sits in Zone 1 or Zone 2.

Counties commonly flagged as Zone 1 in Georgia include:

For a Fannie Mae or Freddie Mac acquisition of a property in these counties, the environmental consultant on the deal is highly likely to recommend testing, even with the increased discretion the post-March 2025 rules allow. The predicted risk is too high to credibly decline. Build-to-rent communities in north Atlanta exurbs, garden-style portfolios in Cobb and Gwinnett, and high-rise rentals in Fulton are the typical situations.

9. Adding radon to a Phase I scope post-March 2025

ASTM E1527-21, the current Phase I standard, lists radon as a non-scope consideration. That means a vanilla Phase I evaluates vapor intrusion from chemical contaminants but does not look at radon at all. A clean Phase I report says nothing about radon either way.

Adding radon to a Phase I is done by writing it into the user-defined scope before the consultant starts work. That mechanism was not affected by the FHFA change. Under the post-March 2025 approach, even when the agency does not require radon, a buyer or lender can still add it to the user-defined scope on any acquisition.

Practical scoping language that environmental consultants commonly use:

• Radon screening at a defined percentage of ground-contact units.
• Short-term protocol (48 to 96 hours, closed-building conditions).
• Report formatted for the agency or lender's receiving template.
• Re-test or follow-up testing if any initial reading exceeds the action level.

For Georgia acquisitions, putting radon in the user-defined scope adds modest cost relative to the deal size and produces a documented baseline. If the property tests clean, the report goes in the file. If it tests elevated, the buyer has the data needed to negotiate mitigation responsibility, credits, or escrows before close.

10. Frequently asked questions