The article examines the situation of patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in the context of the right to healthcare services within the Polish healthcare system. Despite its severe course and significant impact on quality of life, the condition remains insufficiently recognized in both legal and organizational frameworks, partly due to the absence of a clear ICD-10 coding practice. The lack of appropriate regulations and dedicated procedures restricts patients’ access to diagnostics, treatment, and rehabilitation, thereby undermining the constitutional principle of equal access to healthcare. The article also highlights potential violations of patients’ rights as well as the invisibility of the issue in the National Health Fund’s reporting system.