On Oct. 1, U.S. hospitals switch over to a new billing system known as ICD-10, which includes many more medical codes than the previous version. The new system is expected to allow doctors to describe a patient's condition in much greater detail. Jason T. Poplin/U.S. Navy

If you have a doctor's appointment coming up, expect it to take a little more time than usual. U.S. doctors' offices, clinics and hospitals are debuting a new billing system Thursday that classifies procedures and diseases in ways that could help public health researchers and physicians better evaluate and treat patients.

The system's special codes are so specific that doctors can distinguish between a patient bitten by a dolphin and one pecked by a goose, or a patient who falls off a sled versus a snowboard. The new program should improve care by enabling doctors to more accurately capture the details of their patients' condition and treatment.

The mandatory conversion throws a wrench into a medical billing process that has remained largely unchanged for 30 years and is likely to cause headaches for patients as well as physicians. [The new billing code for headache is R51, incidentally --unless it's a headache associated with sexual activity, in which case it's G44.82].

Oct. 1 marks the federal government’s deadline for hospitals all over the U.S. to begin using the new billing system, called the International Classification of Diseases (ICD-10). The primary strength of the system is its nearly 70,000 medical codes which add about 56,000 to the previous version. The U.S. government will pay about $116 million to fully convert its own records to the new system and requires all providers who bill Medicare and Medicaid to use it.

Though hospitals have known about the requirement for years, many expect at least a few bumps along the way. Anyone who visits a U.S. hospital or doctor’s office in the coming week may spend a few more minutes in the waiting room as physicians and nurses struggle to implement the new system. The Workforce for Electronic Data Interchange warned in August that one-fourth of U.S. physicians would not be prepared to make the switch.

The generous coding allows doctors to describe diagnoses in greater detail and could result in a better standard of care. For example, the code now distinguishes between a broken right leg and a broken left leg -- details that were not available under the system used since the 1970s. It may also help public health researchers more easily identify peculiar patterns across patients.

The World Health Organization adopted the new codes back in 1994, but the U.S. launch has twice been delayed due to worries over the cost and magnitude of the switch. Lynne Thomas Gordon, CEO of American Health Information Management Association told HealthcareIT News that her members were expecting a smooth transition. A recent report by the Government Accountability Office suggested “little is known” about the costs of the transition for doctors and hospitals. Estimates have varied widely. One study published last year in the AHIMA journal estimated the costs of switching over a small practice to ICD-10 could be as low as $1,960.