(Undated) -- Iowa is one of the best states in the country for doctors. That's according to a new study by WalletHub, which ranks Iowa as the 9th best state to practice medicine. WalletHub uses 19 key metrics to make its rankings. Iowa's best category is medical opportunity and competition, ranking 6th. Iowa also ranks in the top 10 in average annual wage of physicians, hospitals per capita, insured population rate, and annual malpractice liability insurance rate. WalletHub says the best state to practice medicine is Montana and the worst is Hawaii. A full list of states is available here.