Once a closely-held competitive secret, hospital prices are beginning to shake loose from the grips of healthcare executives in the wake of last week’s unprecedented move by the federal government to publicly share what hospitals bill Medicare for the most common diagnoses and treatments.

The data dump revealed that hospitals across the country, and even in the same communities, charge the government wildly different amounts for the same care, and they receive varying reimbursements from Medicare in return.

While prices for private insurers still remain secret, South Florida hospital executives and industry experts believe more will be revealed as federal healthcare reform rolls out next year — giving consumers more information to decide where to seek medical treatment and creating greater competition in the market.

Steve Sonenreich, chief executive of Mount Sinai Medical Center in Miami Beach, made a public pledge Monday to divulge the contractual rates the hospital charges private insurers for diagnoses and treatments.

“We will post our prices relative to Blue Cross, and Aetna, our contractual prices, and we’ll challenge Baptist and the other systems in the community to do the same,’’ said Sonenreich, who made his pledge during a studio interview on WLRN 91.3-FM with host Tom Hudson.

Also in the radio studio was Brian Keeley, chief executive of Baptist Health South Florida, which manages seven hospitals in the region. Keeley declined to accept Sonenreich’s challenge for price transparency, but acknowledged “That’s where the whole industry is going, undoubtedly.”

By making public the varying hospital charges billed to Medicare, the Obama administration said it hoped to increase transparency from healthcare providers and give consumers the power to be smarter shoppers.

For years, hospitals and government agencies have reported patient satisfaction rates, quality of care measures and other data designed to help consumers.

But for most individuals with health insurance, hospital prices do not affect their decisions because they can only see a doctor in their network, and that doctor has staff privileges at certain hospitals, said Sal Barbera, a former hospital chief executive and now a Florida International University professor of health services administration.

However, Barbera said, “Once this stuff becomes more public, it will have an impact because it’s going to focus attention on it, and hospitals are going to start being accountable.’’

As healthcare reform changes the way consumers pay for insurance coverage, prices will become a bigger factor in consumer decisions, said Steven Ullmann, a professor of health management and policy at the University of Miami.

“We’re moving more from co-pays to co-insurance, which means that instead of paying a dollar amount for an MRI, say $100 out-of-pocket, now they’re moving it toward a percentage of the price, so you might be paying 20 percent,’’ Ullmann said. “So 20 percent of a $1,000 MRI is going to be really different in terms of out-of-pocket costs versus a $3,000 MRI.’’

Another change happening with insurance, Ullmann said, is a move toward high deductible plans, or “consumer driven healthcare,’’ in which patients are responsible for paying a pre-agreed amount of the costs before the insurance kicks in.