['Psychometric study design.', 'To assess the test-retest reliability and convergent validity of the Functional Impairment Test-Hand and Neck/Shoulder/Arm (FIT-HaNSA) in patients with shoulder disorders.', 'Performance tests that assess functional ability of patients with shoulder disorders can provide useful information for making clinical or return-to-activity decisions. No performance-based shoulder test has yet demonstrated sufficient relevance or clinical measurement properties. The FIT-HaNSA examines upper extremity performance during repetitive tasks that emphasize shoulder reaching and static postures and, therefore, has greater relevance for assessing performance.', 'Thirty-six patients with shoulder disorders and 65 healthy controls were recruited for the study. The FIT-HaNSA, the Disabilities of the Arm, Shoulder and Hand questionnaire, the Shoulder Pain and Disability Index, isometric shoulder strength, and shoulder range of motion were assessed at baseline and repeated 2 to 7 days later. Test-retest reliability was described using intraclass correlation coefficient (ICC(2,1)) and standard error of measurement. Pearson correlation coefficients were used to examine the level of association between the FIT-HaNSA scores and the other measures.', 'The ICCs for test-retest reliability for the FIT-HaNSA ranged from 0.89 to 0.97 in the patient group and 0.79 to 0.91 in the control group. The FIT-HaNSA showed high correlation with the Disabilities of the Arm, Shoulder and Hand and the Shoulder Pain and Disability Index, and moderate correlations with shoulder range of motion and muscle strength.'] Does the FIT-HaNSA demonstrate reliability and convergent validity of functional performance in patients with shoulder disorders?