Two different NEPA regimes can touch a 221(d)(4), and which one applies is determined by where the money comes from rather than by what you are building.
Part 50 is the default
24 CFR Part 50 applies to FHA-insured multifamily mortgage projects. Under it, HUD performs the environmental review itself: the HUD approving official makes an independent evaluation of the environmental issues and makes the environmental finding.
Part 50 provides three levels of review — categorical exclusion, environmental assessment, and environmental impact statement — and the level depends on the action and the site. It also carries a hard prohibition: an applicant may not acquire, rehabilitate, convert, lease, repair or construct the property until HUD approval. Review must be complete before the applicable program decision point.
Part 58 enters through your other funding sources
24 CFR Part 58 applies when a state, tribe or unit of local government — the “responsible entity” — assumes HUD’s environmental review role. The covered programs are the community development ones: CDBG, HOME, public housing and HOPE VI, McKinney-Vento, NAHASDA, Section 184, HOPWA.
So a pure 221(d)(4) is Part 50. A 221(d)(4) layered with HOME, CDBG or Housing Trust Fund money brings a Part 58 review into the same transaction.
HUD’s position on the overlap, from Housing Notice H-2024-10, is that a Part 50 review can incorporate the Part 58 program, but a Part 58 review cannot substitute for a Part 50 review. Combining into one Part 50 review is recommended for efficiency.
Why Part 58 takes longer
The additional time is written into the regulation. Part 58 requires a publication and objection cycle that Part 50 has no equivalent of:
- The responsible entity publishes notices and observes comment periods — a FONSI notice runs 15 days published or 18 days mailed; a notice of intent to request release of funds runs 7 days published or 10 days mailed; a combined notice runs 15 or 18 days.
- It then submits a Request for Release of Funds and Certification on Form HUD-7015.15.
- HUD and the public then have a 15-day objection period.
- No HUD assistance may be committed until HUD approves the release of funds.
Add those up and the statutory minimum is roughly a month of pure calendar, before anyone has reviewed anything substantively. The second reason is institutional: the responsible entity is a local government with its own staffing, its own agenda and its own queue, and neither you nor your lender has any leverage over it.
Form HUD-4128 is retired. It is HEROS now.
Under Housing Notice H-2024-10, environmental reports for covered transactions must be submitted through HEROS, HUD’s Environmental Review Online System, and Form HUD-4128-OHF is no longer accepted. The current MAP Guide carries a section on HEROS environmental reports. Any checklist or article still referencing form 4128 is out of date.
On timing, HUD’s guidance for multifamily FHA partners is specific: for lenders using pre-application processing, the environmental review must be in HEROS and assigned to HUD at pre-application. Consultants and lenders prepare and enter the review; HUD reviews it, completes the compliance steps, and makes the final determinations on historic preservation, floodplain, contamination mitigation and the rest.
What changed in May 2026
Mortgagee Letter 2026-04, issued 4 May 2026 and effective immediately for any application not yet at initial endorsement, revised several Chapter 9 requirements:
- Railroad vibration removed as an environmental requirement — HUD now treats it as an underwriting concern rather than an environmental one.
- Pressurized pipelines revised to a 10-foot setback from the easement boundary for pipelines exceeding 200 psi.
- High-voltage lines and fall hazards revised to require siting at a distance of at least 50% of the height of any support structure, with an ASCE-7 engineer’s report as the alternative path.
- Noise-sensitive outdoor uses newly defined. Pools, playgrounds and shared gathering spaces count; dog runs, trails, car washes and rooftop grill areas do not. The underlying standards remain 24 CFR Part 51 Subpart B — 65 dB exterior, 45 dB interior.
That last item is genuinely useful. Site plans were previously being redesigned around outdoor amenities that HUD now says are not noise-sensitive.
How to manage it
Start the environmental work before you think you need to, and find out early whether any funding source in your stack drags Part 58 into the deal. If one does, the responsible entity’s calendar — not HUD’s — becomes your critical path, and it is worth making direct contact with that office at the concept stage rather than at submission.