In the case of Tarquinio v. Johns Hopkins University Applied Physics Lab (No. 24-1432), decided by the Fourth Circuit on June 25, 2025, the court addressed whether an employer had a duty under the Americans with Disabilities Act (ADA) to accommodate an employee who refused to provide medical documentation supporting her request for a COVID-19 vaccine exemption. Sally Tarquinio, an employee at Johns Hopkins Applied Physics Lab (APL), sought a medical exemption from APL’s COVID-19 vaccination requirement due to a condition she described as “Lyme-induced immune dysregulation.” APL, as a federal contractor, was required at the time to mandate vaccination in line with federal guidelines. Tarquinio declined to allow her doctors to communicate directly with APL or provide updated medical records to substantiate her request. As a result, APL terminated her employment for noncompliance.

Tarquinio subsequently filed suit in the District of Maryland, claiming APL failed to accommodate her disability, wrongfully terminated her, and made impermissible medical inquiries under the ADA. The district court granted summary judgment in APL’s favor, reasoning that Tarquinio had not adequately notified her employer of a work-related limitation requiring accommodation. On appeal, the Fourth Circuit affirmed. Writing for the court, Chief Judge Diaz emphasized that under the ADA, an employer's duty to accommodate arises only when it has actual knowledge not merely of a diagnosis, but of a condition that imposes specific limitations on an employee’s ability to perform her job. The court concluded that Tarquinio failed to establish such notice. Her refusal to provide documentation substantiating her disability or consent for her employer to obtain verification of her disability directly from her health care provider effectively prevented APL from understanding the nature and extent of her claimed limitations.

The court also clarified the role of the “interactive process” required under the ADA, which involves an ongoing dialogue between employer and employee to identify appropriate accommodations. While employers must participate in good faith, this process only begins once the employer is made aware of a work-related limitation. The Fourth Circuit held that Tarquinio’s lack of cooperation frustrated this process and excused APL from any further obligation. APL did not dispute that Tarquinio had a disability; it disputed that the disability prevented her from being vaccinated. Without evidence that the vaccine was contraindicated for her, there was no legal duty to accommodate.

This decision has significant implications. It underscores that employees seeking ADA accommodations must not only demonstrate they have a covered disability under the ADA, they also must also establish with medical documentation that the disability limits their ability to perform an essential function of their job. Employers, in turn, are permitted to request documentation to confirm the existence of a functional limitation. If that information is not available or the employee refuses to disclose it, the employer lawfully may deny the accommodation.

Employers often are reluctant to aggressively pursue medical documentation. Employees often claim privacy rights that are not applicable to the circumstances and employers get cold feet. The Tarquinio ruling is welcome certainty that the employee’s failure to provide such information may lawfully result in the denial of accommodation and even termination. Employees seeking an accommodation must (a) establish that they have a disability, with medical documentation if the disability is not obvious; (b) establish with medical documentation that the disability impacts their ability to perform one or more essential functions of their job; and, (c) cooperate throughout the interactive process.

Employers should ensure their accommodation policies include references to employees requirement to provide the necessary medical documentation supporting accommodation requests as well as the consequence for failing to provide such information or engaging in the interactive process in good faith. Employers should work closely with counsel to ensure they are properly (and consistently) handling ADA cases, especially in more sensitive cases where the employee is not cooperating and an accommodation denial will result in employment termination.