Healthcare real estate is among the most energy-intensive commercial property in the country. Operating rooms, imaging suites, laboratories, and 24/7 patient care environments demand sophisticated HVAC, lighting, and building envelope systems, and those systems carry real capital cost. For more than two decades, the Section 179D Energy-Efficient Commercial Buildings Deduction has helped offset that investment by rewarding owners, developers, and designers who build (or upgrade) to higher efficiency standards.
For medical property stakeholders, 179D has always been a strong fit. But the runway is now short. Under the One Big Beautiful Bill Act (OBBBA), Section 179D is scheduled to terminate for property whose construction begins after June 30, 2026. With that date now weeks away, hospitals, health systems, medical office building (MOB) developers, and ambulatory care investors should be evaluating eligibility before the window closes.
What Section 179D Offers
Section 179D allows a federal tax deduction for the installation of energy-efficient improvements to commercial buildings, including new construction, renovations, and additions. Qualifying improvements fall into three system categories: interior lighting, HVAC and hot water systems, and the building envelope (walls, roof, windows, insulation, and doors).
Eligible projects can generate a deduction of up to $5.81 per square foot for property placed in service in 2024 (indexed annually), provided prevailing wage and apprenticeship requirements are met. For a single 200,000-square-foot hospital wing, that potential deduction is meaningful, and for a portfolio of MOBs or surgery centers, the impact compounds quickly.
A note that often surprises clients: 179D is not limited to building owners. For government-owned and certain tax-exempt buildings, a category that captures a large share of the healthcare landscape, including municipal hospitals, public university medical centers, and many nonprofit health systems, the deduction can be allocated to the designer. That includes the architect, engineer, or design-build contractor responsible for the energy-efficient systems. For firms designing hospitals, clinics, or medical campuses for tax-exempt entities, 179D has long been a quiet but powerful incentive.
Why Medical Properties Are Particularly Well-Positioned
Healthcare facilities tend to carry the kind of building characteristics that make 179D analyses productive.
Hospitals and surgery centers require precise air handling, pressurization, humidity control, and filtration. These HVAC systems are typically engineered well above baseline commercial standards, and often well above the 179D efficiency benchmarks. Modern medical environments also rely heavily on LED systems, tunable lighting in patient rooms, surgical lighting, and integrated controls, and lighting alone can drive a substantial portion of a 179D deduction. New medical campuses and major renovations frequently include high-performance glazing, advanced insulation, and roofing systems built to support both energy and infection-control objectives. And because health systems often build in phases, new towers, parking structures, MOBs, and outpatient facilities developed over multiple years, each phase placed in service can be evaluated on its own merits.
Eligible property types frequently include hospitals, ambulatory surgery centers (ASCs), medical office buildings, urgent care facilities, behavioral health centers, skilled nursing and senior care facilities, dental and veterinary clinics, and life sciences and laboratory buildings.
What the OBBBA Sunset Actually Means
The One Big Beautiful Bill Act, signed into law in 2025, ended several long-standing energy tax incentives. For Section 179D, the law sets a firm cutoff: property whose construction begins after June 30, 2026, will no longer qualify for the deduction. Projects that begin construction on or before that date remain eligible under the existing rules, provided all other requirements are satisfied and the property is eventually placed in service.
That distinction matters. The deadline is tied to the start of construction, not the placed-in-service date. For owners and developers with projects already underway, or projects that can reasonably begin within the next several weeks, 179D may still be on the table for years to come, even if the building is not completed until 2027 or beyond.
Documentation will be critical. Establishing a defensible construction start date, maintaining contemporaneous records, and pairing the project with a proper third-party certification are all essential to preserving the deduction through any future review.
What to Do Before the Deadline
For medical property owners and developers, the practical next steps are straightforward. Review your active and near-term pipeline, any project breaking ground on or before June 30, 2026 should be evaluated for 179D potential. Look at recently completed and in-progress work as well; projects placed in service in open tax years may still be eligible for 179D under the rules in effect at the time of construction, and certain prior-year opportunities can sometimes be captured through amended returns or accounting method changes. Designers working with tax-exempt healthcare clients should pursue allocation letters proactively, since allocations are often easier to secure earlier in the project lifecycle.
A qualified analysis will determine eligibility, model the deduction value, and identify documentation requirements before any commitments are made.
After the Sunset: Claiming 179D Through Form 3115
Even after Section 179D sunsets, the deduction does not necessarily disappear for property that was eligible while the rule was in effect. Many medical property owners and designers placed energy-efficient buildings in service in earlier tax years without ever claiming 179D — often because they were unaware of their eligibility or because no certification was performed at the time. By filing Form 3115, Application for Change in Accounting Method, taxpayers can capture those missed deductions in a current tax year through a single Section 481(a) catch-up adjustment, without amending prior returns. After June 30, 2026, Form 3115 is expected to remain the primary route for unlocking 179D value on legacy medical buildings.
A few guardrails apply. The property must have been eligible under the 179D rules in effect when it was placed in service, a qualifying energy certification still has to be completed, and Form 3115 changes only the timing of the deduction — it does not revive eligibility for property whose construction begins after the OBBBA cutoff. Done correctly, this is a compliance-safe procedure with decades of precedent; done incorrectly, it can create exposure. Look-back 179D work should be handled by a team with deep engineering and tax-law experience.
Why Engineering-Based Analysis Matters Here
Section 179D is a compliance-sensitive deduction. It requires energy modeling under ASHRAE standards, on-site inspection by a qualified individual, and a formal certification package. Missteps, incorrect baseline assumptions, inadequate documentation, or an unqualified certifier, can compromise the deduction and create exposure under IRS review.
CSSI’s approach is engineering-first. With more than 23 years of experience and over 60,000 completed studies, our team applies detailed engineering analysis and deep tax law expertise to every 179D engagement. The goal is not simply to claim the deduction, but to produce work that is clear, defensible, and built to withstand IRS scrutiny.
The Window Is Closing; But It Is Still Open
For medical property owners, developers, and designers, Section 179D has been one of the most valuable and underused incentives in the tax code. The OBBBA sunset does not erase the opportunity, it sharpens the timeline. Projects that begin construction by June 30, 2026 remain eligible, and prior-year work may still be reviewable depending on the facts.
If you own, develop, or design healthcare facilities, now is the time to take a closer look.
Calculate how much you could potentially be saving through Section 179D now!
Frequently Asked Questions
My hospital project won’t be finished until 2028. Can it still qualify for 179D? Possibly, yes. The OBBBA cutoff is tied to when construction begins, not when the building is placed in service. If construction starts on or before June 30, 2026, the project may remain eligible under the existing 179D rules even if completion is years later. Proper documentation of the construction start date is essential.
Our health system is a nonprofit. Does that mean 179D doesn’t apply? It often means the opposite. Because nonprofit and government-owned healthcare facilities don’t pay federal income tax, the building owner can’t use the deduction directly, but the deduction can be allocated to the designer (architect, engineer, or design-build contractor) responsible for the energy-efficient systems. Many designers working on hospitals and medical campuses are surprised to learn how much 179D value they may be leaving on the table.
What kinds of medical buildings typically qualify? A broad range, including hospitals, ambulatory surgery centers, medical office buildings, urgent care clinics, behavioral health facilities, skilled nursing and senior living communities, dental and veterinary practices, and life sciences and laboratory buildings. Both new construction and substantial renovations can be evaluated.
How much could the deduction actually be worth? For property placed in service in 2024, the deduction can reach up to $5.81per square foot when prevailing wage and apprenticeship requirements are met (the cap is indexed annually). Actual benefit depends on building size, system efficiency, and the results of the required energy modeling. A free analysis can provide a realistic estimate before any commitment is made.
Can we look at buildings we’ve already placed in service? Often, yes. Projects placed in service in open tax years may still be reviewable under the rules in effect at the time of construction, and in many cases the deduction can be captured through amended returns or an accounting method change. This is worth exploring quickly, since open tax years close on a rolling basis.
What happens after June 30, 2026? For projects whose construction begins after that date, Section 179D will no longer be available. Other tax strategies, including cost segregation, remain valuable tools for medical property owners and developers, and CSSI can help evaluate the full picture.
