AM Best Removes From Under Review With Positive Implications and Upgrades Credit Ratings of National General Holdings Corp. and Its Subsidiaries OLDWICK, N.J.--(BUSINESS WIRE)--AM Best has removed from under review with positive implications and upgraded the Long-Term Issuer Credit Rating (Long-Term ICR) to “a” from “bbb-” of National General Holdings Corp. (NGHC) (headquartered in New York, NY). Additionally, AM Best has removed from under review with positive implications and upgraded certain Long-Term Issue Credit Ratings (Long-Term IRs) of NGHC. At the same time, AM Best has removed from under review with positive implications and u