Want to know what your local hospital charges for treating a heart attack? Wonder how it compares with hospitals across the state or the country?

For the first time, that information is available to the public for free. And it turns out the prices vary dramatically.

The federal government on Wednesday released a list of what hospitals charge for the 100 most commonly billed services. The data is from 2011, and lists the average amount charged to Medicare by each hospital and the average amount paid.

The charges are akin to sticker price. Medicare, Medicaid and private insurance generally pay significantly less than hospitals’ listed charges. But people without health insurance are often stuck with bills for the sticker price.

The degree of variation in prices surprised federal health officials.

In some cases nationally, charges for one hospital were as much as 20 times higher as those for another, said Jonathan Blum, director of the Center of Medicare at the federal Centers for Medicare and Medicaid Services.

The variation was so large that possible explanations for it — such as differences in patients’ health or additional costs related to teaching hospitals — “don’t add up to us,” Blum said during a webinar with reporters.

In Connecticut, the variations in the charges were less than what Dr. Mary Cooper, vice president and chief quality officer at the Connecticut Hospital Association, had expected.

She noted that hospitals in Connecticut already report charge information to the state Office of Health Care Access, and said that public reporting might account for the smaller variation.

According to the data released Wednesday, charges for treating a patient with a heart attack in Connecticut range from $9,153 at MidState Medical Center in Meriden to $33,908 at Waterbury Hospital. The average amount the hospitals got paid for treating Medicare patients was significantly less: MidState got $5,124, while Waterbury got $6,388. (Yale-New Haven Hospital, which charged $24,094, got paid the most in the state on average, $8,655.)

For a major joint replacement, prices ranged from $23,063 at Charlotte Hungerford Hospital in Torrington to $72,393 at Greenwich Hospital. (Average amount paid: $14,351 at Charlotte Hungerford, and $15,402 at Greenwich.)

Bristol Hospital got paid the lowest amount for a major joint replacement ($13,794, compared with a sticker price of $37,258). UConn’s John Dempsey Hospital got the most: $23,207, compared to a charged price of $32,652.

What explains the differences in sticker price?

Cooper said charges are specific to facilities and communities. Hospital facilities vary widely in age across the state, she said, and a hospital that’s spending money to bring its infrastructure up to regulatory standards will have different kinds of charges than one that built a new facility in recent years. Similarly, hospitals with many patients who don’t get care until their illnesses have progressed might have a different charge structure than one that tends to see patients who get more preventive care. And, she noted, while some hospitals have lots of technology for specialized care, others are community hospitals that tend to send patients with the most complex needs to other facilities.

Brian Cook, a spokesman for the Centers for Medicare and Medicaid Services, said releasing the data was intended to empower consumers to ask about variations in prices. He noted that while insured patients don’t pay sticker price, the data illustrate what people who are uninsured or underinsured are paying.

The data represent a first step in transparency, Cooper said, but she added that they’re difficult for consumers to navigate.

“This broke the ice, but if I were looking at this for my own purposes, I wouldn’t have any more knowledge about how to make a decision than I do now,” she said. “And I think that we in health care now need to take data that are available, and we’re committed to the concept of transparency, and now we need to make it useful for people.”

You can download the data as an Excel file by clicking here.