The ability to transfer electronic medical records from one doctor or hospital to another is essential to the smooth functioning of the health care system and to providing the best possible care to patients. Yet all too often these transfers are being blocked by developers of health information technology or greedy medical centers that refuse to send records to rival providers.

This will not be an easy problem to fix, but some possible approaches were detailed in a report to Congress last week from the Office of the National Coordinator for Health Information Technology, a unit of the Department of Health and Human Services.

The full extent of the problem is difficult to assess, according to the report, mainly because of contractual restrictions imposed by software developers on their customers. Even so, the office deduced from various sources — including customer complaints and interviews — that some software developers and medical centers have deliberately blocked the sharing of information. It did not name the parties because it could not determine with any certainty whether some of the information was blocked for legitimate reasons, like concern for patient privacy.

The motivations for hoarding or restricting data appear to be mostly business-related; for instance, companies lock customers into costly proprietary technology and often charge exorbitant fees for sending or receiving information. Some hospitals, critics say, won’t share information with doctors outside their own networks, lest they lose control of the patient and erode their dominance of a local market. Larger hospital systems that share health information internally sometimes won’t do so with competing hospitals and unaffiliated providers.