Which of the following is NOT a claim form used by physicians?

The UB-04 form is primarily utilized by institutional providers rather than individual physicians. This form is designed for billing services rendered by hospitals, skilled nursing facilities, and other types of healthcare institutions. In contrast, the CMS-1500 form is specifically intended for use by non-institutional providers, such as physicians and practitioners, to submit claims for services rendered to patients.

The CMS-1491 and CMS-1600 forms are not commonly recognized claim forms within the physician billing context. The CMS-1491 is generally associated with specific types of claims, and the CMS-1600 is not a standard claim form used in physician billing. Therefore, identifying the UB-04 as the correct answer is essential, as it is not used by physicians for submitting claims, distinguishing it from the other forms tailored for physician use.