A federal appeals court has just made it easier for employers to keep safety-sensitive workers off the job over medical risk, even when the employee’s own doctors say he is fit to return. The ruling does not turn on artificial intelligence or new HR software, but it validates the exact kind of structured, evidence-based fitness assessment that a growing wave of workforce risk platforms and occupational health systems are built to standardize, and HR leaders in safety-sensitive industries should read it as a green light to formalize those programs rather than handle them case by case.
What the Eighth Circuit decided
On August 11, 2026, the U.S. Court of Appeals for the Eighth Circuit affirmed summary judgment for Union Pacific Railroad Co. in Christensen v. Union Pacific Railroad Co., a disability discrimination case brought by Ross Christensen, a conductor of more than ten years who suffered an ischemic stroke in January 2015. Christensen recovered quickly. Within four days, most of his neurological symptoms had resolved, and his treating neurologist cleared him to return to work within weeks. Union Pacific did not let him back on a train.
The railroad’s medical department instead ran Christensen through repeated fitness-for-duty evaluations. Its chief medical officer and a second reviewing physician concluded he carried an elevated, if statistically low, risk of a future seizure tied to the location of his stroke and a related brain hemorrhage. Leaning on Federal Motor Carrier Safety Administration guidance for commercial drivers, Union Pacific imposed a five-year work restriction, later extended when Christensen sought reinstatement in 2018. He never returned to the job and sued in 2023 under the Americans with Disabilities Act.
The “direct threat” defense did the work
The ADA lets an employer defeat a disparate treatment claim if it proves the employee posed a “direct threat,” a significant risk to safety that reasonable accommodation cannot eliminate. To win that defense, an employer must show its call was the result of an individualized assessment, was objectively reasonable, and rested on the best available medical evidence. The Eighth Circuit found Union Pacific cleared all three bars: multiple fitness-for-duty reviews, reliance on named treating and reviewing physicians, and use of federal safety-agency guidance that the court called evidence-based.
Christensen’s strongest argument was that his own doctors disagreed with Union Pacific’s physicians and cleared him to work. The panel rejected that as beside the point. Writing for the court, Circuit Judge Shepherd of the Eighth Circuit stated that “while a reasonable jury could perhaps conclude from Christensen’s evidence that Union Pacific misjudged the safety risk he posed, there is nothing in the record that would allow a jury to conclude that Union Pacific’s judgment was so off-base as to be objectively unreasonable.” The legal standard, the court noted, asks only whether the employer’s medical opinion was objectively reasonable, not whether it was correct.
Why this matters beyond one railroad
Union Pacific has now won this same defense in more than one appellate circuit this year, and the pattern is instructive for any employer running safety-sensitive roles, not just rail. The court drew a sharp line between this case and EEOC v. Drivers Management, LLC, a 2025 Eighth Circuit decision where an employer lost the same defense after making “a few general calls” to justify barring a deaf driver, a process the court called stereotype-driven rather than evidence-based. The difference was documentation and process: multiple medical evaluations, named physicians, and a defined guideline the company could point to, versus an ad hoc judgment call.
That distinction is exactly what occupational health and workforce risk software promises to operationalize: consistent intake of medical records, a defined evaluation protocol, and an audit trail showing each restriction traces to a named clinician and a cited standard. Employers without that infrastructure are the ones most exposed if a similar case reaches summary judgment, because the ADA’s direct threat defense turns on whether the process was rigorous and documented, not simply whether the final call happened to be right.
What it means for the HR leader
For any HR or risk leader overseeing safety-sensitive positions (transportation, manufacturing, healthcare, utilities), the ruling reinforces three practical points. First, an individualized medical review beats a blanket policy every time a direct threat defense is tested in court; a return-to-work decision built on a named physician’s evaluation of that specific employee’s records is far more defensible than a categorical exclusion. Second, citing an established external standard, even one later partially withdrawn, strengthens the record; the court noted the FMCSA guidance Union Pacific relied on remained “evidence-based and developed through a consensus of medical experts” regardless of its later removal from the agency’s website. Third, disagreement among doctors is not a liability by itself. Employers do not need every physician to agree, only a reasonable basis for the decision they made.
The case also underscores a governance point for any HR technology used to manage these calls. If a platform is going to automate or standardize fitness-for-duty tracking, restriction reviews, or return-to-work workflows, it needs to preserve exactly the kind of individualized record the Eighth Circuit relied on: which physician made the call, what records they reviewed, and which external guideline they applied. A system that produces a uniform, unexplained restriction is not meaningfully different from the “few general calls” that lost in Drivers Management.
What to do next
Employers with safety-sensitive workforces should audit their current fitness-for-duty process against the three-part test the Eighth Circuit applied: is each decision individualized, is it grounded in a named clinician’s review of that employee’s specific records, and is it tied to a defined, citable standard rather than internal habit. Programs that can answer yes to all three are the ones that will survive a direct threat challenge; programs that cannot should be formalized before the next case, not after one is filed.
Source: Eighth Circuit Court of Appeals opinion, Christensen v. Union Pacific Railroad Co. (CourtListener)
Related: Court Ruling Expands ADA Duty to Reassign Workers and Most US Workers Have Skipped Work Over Safety Fears.
