Review of prevailing scales/methods of impairment/disability evaluation reveals that there is no uniform definition to assign impairment and different countries assign different impairment score for similar impairment of structure or function. An integrated method of disability evaluation aims to assign an optimum whole person disability for global application. It applies the principles of homunculus for assigning impairment to the motor and sensory functions. It also applies “weighted score” for functional/structural impairment. It considers the burden of disease (e.g., AIDS), the burden of treatment (e.g., chemotherapy in malignancy), and replacement of implanted device (e.g., pacemaker or prosthesis). It further, considers the failure of the implanted device (e.g., cardiac pacemaker), failure of treatment (e.g., AIDS), the risk of mortality (end-stage renal failure/hepatic failure/heart failure) and stigma (AIDS) to define impairment. Integrated evaluation of disability applies severity scale, that is, mild, moderate, severe, profound, and complete impairment to grade the severity of impairment of function/structure. Further, integrated evaluation of disability describes impairment class which denotes the severity of impairment for individual function/structure. Hence, the percentage of impairment may vary for class “1” to every function/structure, and similarly for class “2,” class “3,” class “4,” and class “5.” Integrated evaluation of disability compares its impairment score with that of Australia, Canada, Europe, Korea, India, Japan, and United States of America. Furthermore, Modified Delphi Process’, expert opinion and pilot study using clinical models provide validation for assigning impairment.