Diane Aiello's annual physical went well last spring. It was only when she got the bill that her blood pressure shot up.

Ms. Aiello, an unemployed attorney, had checked with Highmark before her physical to find out what her financial obligation would be. Under her plan with the insurer, she faced a $25.25 co-payment.

On April 28, she went to Shea Medical Center, located in the Shadyside Medical Building on the UPMC Shadyside campus, and underwent a routine 20-minute exam with no lab work or X-rays.

To her surprise, a month later Ms. Aiello, 61, received an explanation of benefits from Highmark saying she might owe the provider another $91.95 for unspecified "clinical service."

"I called Highmark and asked, 'What is this?' and they said they didn't know."

It was only after UPMC started leaving phone messages at her Munhall home that she learned the $91.95 was a "facility fee."

It turns out that she and many other patients are expected to pay facility fees, which cover office overhead expenses such as utilities and maintenance, when the doctor's office is part of a hospital campus -- or, sometimes, even if it isn't -- in cases where the physician practice is owned by the hospital or a health system.

"It depends on the contractual arrangement between the hospital and the physician's office practice," said Highmark spokesman Michael Weinstein.

West Penn Allegheny Health System spokesman Dan Laurent said that the health system also has fees for visits at facility-based medical practices, as allowed by Medicare.

While facility fees are not new, they appear to be more common or at least getting more attention.

Last year, the Cleveland Clinic faced a storm of public criticism when it instituted facility fees at some of its outlying family health centers. One health center patient told the Cleveland Plain Dealer that her medical bill increased 63 percent as a result of the additional fee.

"How would [a patient] know that the doctor is going to charge them but the hospital is going to want some money, too?" asked Pat Palmer, founder of the Salem, Va.-based Medical Billing Advocates of America.

It may look like the same four walls and examining table to the patient, she said, but if a physician bills a visit as a hospital-based visit rather than an office-based visit, the cost for simple procedures can triple.

In Ms. Aiello's case, the facility fee appears to have come into play because last fall she switched from a group insurance plan to an individual health plan. Because of that, a patient "most likely has more out-of-pocket expense with the individual plan with Highmark versus the group plan," said UPMC spokesman Paul Wood.

Many individual plans, particularly those with high deductibles, do not cover facility fees until the yearly deductible is met, said Mr. Weinstein, who said privacy laws prevented him from commenting on the specifics of Ms. Aiello's situation.

"We're starting to see this a little bit more as more physician practices are owned by hospitals," he said.

While physicians will submit a claim to the insurer for their professional fee, "in many cases the hospital can also submit a claim -- a facility fee -- because the service was performed in a wing or a unit of the hospital."

Ms. Aiello believes that is unfair, noting that tax-exempt hospitals already can claim depreciation on the facility.

She also noted the inscription on a plaque in Shea Medical's reception room: "In grateful appreciation for the generosity of Irene C. Shea which has made this facility possible."

Why, she wondered, is she being charged extra for using a facility built with someone's donation?

She refused to pay the fee at first and filed appeals with both the state insurance and health departments, which she said have not been resolved.

But she recently agreed to a $15-per-month payment plan after UPMC said it would turn her unpaid bill over to a collection agency.

She also changed doctors.

"I told my [primary care physician] that I can't afford to walk into the building."

"Money Q&A" and "Company Town" are featured exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.