No. Embalming is not required for cremation in any state if refrigeration is available; however, there are three basic reasons to embalm and the choice may depend on what your plans are for a funeral service or public viewing.
Refrigeration or embalming are commonly used to protect loved ones and anyone coming into contact with the deceased in the event of any contagious disease or infection. Embalming is mandatory if the deceased is to be shipped out of the country or a long distance.
In lieu of refrigeration, embalming is necessary if the body is to be held beyond 48 hours or if the deceased is to be transported. Embalming is mandatory if the body is to be shipped out of the country. In most cases an open casket will not be an option unless embalming is performed within 48 hours. The reasons for delaying a cremation include waiting on a signed death certificate, the body being held by the Coroner or Medical Examiner, and for practical reasons such as waiting for loved ones and friends to travel to the place where a funeral and/or memorial will take place before cremation.
If there will be a visitation and funeral service with an open casket, embalming would typically be necessary so that the decedent will look aesthetically pleasing to those who knew him or her.