OLDWICK, N.J.--(BUSINESS WIRE)-- #insurance--AM Best has assigned Long-Term Issue Credit Ratings (Long-Term IR) of “a” (Excellent) to the $500 million, 4.60% senior unsecured notes, due 2031, and $1 billion, 5.15% senior unsecured notes, due 2036, issued by The Progressive Corporation (Progressive) (Mayfield Village, OH) [NYSE: PGR]. The outlook assigned to these Credit Ratings (ratings) is stable. The assigned Long-Term IRs consider the rating profiles of Progressive's insurance subsidiaries, as well as th.