Depends on your degree and line of work. For example, if you are a Doctor, Pharmacist, Nurse or Health Care professional, you may need credential evaluation to obtain the necessary licenses to practice that profession in USA. So to apply for a license, you may need to prove that you have education in the relevant field. Credentialing agencies like World Education Services (WES) or Global Credential Evaluators (GCE) are two such agencies who will do the credential evaluation for a fee. But if you are looking for work in fields where license requirements are not there (example : IT, Engineering, etc.) employers may allow you to work without credential evaluation. They may accept your foreign degree.