It is correct. Welcome to provider-based billing.
When private practices are purchased by a hospital, there are two options. One is to keep the practice as just that-- a practice where the services are billed as office services. This happens most frequently if the hospital has an associated physician corporation; a group of practices under the umbrella of the hosptial, but a separate business.
What you're describing is the second option, where the practice becomes a department of the hospital. Essentially, the practice now becomes an outpatient department (POS 22), and as such the 'practice' can bill both a professional fee and a technical fee, just as other outpatient services are billed (think about a visit to the emergency room...you get a hospital bill for the ED visit, and a bill for the ED physician's work).
What's happened with your husband's cardiology practice is that you're getting a bill for the physician's E&M, provided in the outpatient setting, and you're getting a bill for the hospital's share of the overhead---as an outpatient department, the hospital can bill for their reimbursement of the cost of providing the service; nursing care and testing for example, just as they would for any other outpatient visit. It costs more because the hospital (being a facility) can get reimbursed more for diagnostics and procedures than if it was done in the office AND you still get to bill profesional and technical services for both.
The physician's bill is submitted on a 1500 form and the outpatient hospital bill is submitted on the UB. There is occasionally more cost transferred to patients, as you've experienced, but it is legal, and becoming much more prevalent as private practices can no longer afford to stay independent.