The new policy, which also bars from hiring those who use tobacco without lighting up, requires applicants to be tested for nicotine, which will be added to drug-screening urine testing, The Arizona Republic reported.
The company says it's fitting a healthcare giant should lead by example, given the overwhelming evidence of the lethal dangers of smoking and health hazards of second-hand smoke.
"Humana is dedicated to helping our employees take charge of their own health," said Dr. Charles Cox, Humana vice president and market medical officer for Arizona, Nevada and Utah.
Arizona law affords tobacco users no recourse in the courts, legal experts told the Republic.
"Being a smoker is not a category that is protected under the law," said Lisa Coulter, an attorney with Snell and Wilmer in Phoenix.
Humana joins other a burgeoning number of companies, many in healthcare, targeting employee or potential employee tobacco use.
Humana pointed to U.S. Centers for Disease Control and Prevention statistics indicating smoking causes about 443,000 deaths each year.
"Cigarette smoking increases the risk of cancer and shortens life spans," Humana spokesman Ross McLerran said. "We're trying to provide a workplace that is safe and healthy. We do care about the health of our associates."