**The procedure to become a CPA after CA is same without CA**. For an Indian CA, there is no exemption in CPA. **You have to give all 4 papers**. One has to register first (Online : www.aicpa.org) to write the exams. Since the exams are conducted ONLY in the U.S - now even Online through prometric centres (although there are sites in Guam, Puerto Rico and the U.S. Virgin Islands)
AICPA is a parent body and the requisites to sit for Exam is decided by the selected States. Once we select the State eventually the state will ask for our qualification and experience for evaluation purpose. **As of now only Colorado State recognizes Indian CAs and so does not require evaluation before admission to sit for the exam.**
After passing the exam, and meeting necessary experience or other requirements, the State Board of Accountancy would then issue you a CPA license. Once you have been issued a CPA license, you are eligible for full membership in the AICPA) anybody who is eligible to write the CPA exams AND who can enter into the U.S with a valid visa (visitor or other visas) can write these CPA exams. If you don't have the valid work permit to work in the U.S, you can still pass the CPA exams but you cannot get the license (some states require no work experience too...).