But providers, who must use the codes describing patients' illness and injuries to get paid, are braced for problems: The sweeping revision, more than a decade in the making, expands the current nomenclature from about 14,000 codes to 68,000.
Physicians' offices, hospital systems and the federal government have spent billions on training to get ready for this transition. Detractors, however, say it's too costly and not worth it. Some experts worry that coding errors could result in claims getting denied and delayed. And some doctors' practices are taking out short-term loans to ensure steady cash flow.
The updated designations, officially known as the 10th version of the International Classification of Diseases, or ICD-10, are supposed to help the health care system more quickly identify warning signs of epidemics like Ebola or potential flu pandemics. The new codes are also supposed to improve the accuracy of payments to providers, reduce fraud and assist researchers in better understanding and treating complex medical conditions.
For example, doctors will now document whether surgery was done on the left or right side of the body. They'll indicate whether a patient is making a repeat visit, which could suggest more serious health issues.
Yet the massive expansion of codes, a response in part to doctors' demands for greater accuracy in describing conditions, strikes many as another very thick layer of red tape. And some circumstances seem so far-fetched that web sites and twitter hashtags -- including #theresacodeforthat -- have sprung up just to make immense fun of the more bizarre. Some places are selling illustrations and playing cards. At least one twitter handle, @everyicd10, is tweeting out every single code.
Among the most popular:
• Bitten by macaw: W61.11
• Prolonged stay in weightless environment: X52
• Unspecified balloon accident injuring occupant: V96
•Injured in a prison swimming pool: Y92.146
Many of the codes fall into optional fields and aren't likely to be used. Most doctors rely on a narrow set for conditions they see on a regular basis and won’t need to learn new ones that aren’t associated with their practice areas, said Aaron Albright, a spokesman for the federal Centers for Medicare and Medicaid Services.
But it's not exactly clear how this will all play out.
Emergency department doctors, for example, say it won't be that much of a burden to specify where someone is having abdominal pain and whether it's the first time the person has been seen.
"The only place it's really annoying is when they want a lot of data about some types of trauma, like motor vehicle crashes," said Howard Mell, an emergency department physician who works in Winston-Salem, N.C.. "Was it a collision between a car and a truck, or a car and a car?"
Federal health officials say the current system hasn’t been updated for over 35 years, and the United States is the only major industrialized country that hasn't switched to the ICD system that the World Health Organization published in 1992. The first ICD was in 1900 and there have been several versions. Most other industrialized countries transitioned long ago, adopting a version that best suited their needs.
The U.S. government delayed numerous times, in part because of opposition from groups like the American Medical Association. The AMA contends that the clinical data to be gained from the extra codes isn't worth the added burden on doctors.
Federal officials have announced a one-year grace period to give participants the flexibility to adapt. The trade group America's Health Insurance Plans says private insurers are ready to go, but AMA President Steven J. Stack says the impact of the switch won't be fully understood until after claims processing begins.
"The resulting confusion and inconsistency in claims processing would create unnecessary administrative costs and take resources away from patient care,” he warned in a statement this week.
The National Center for Health Statistics, part of the Centers for Disease Control and Prevention, developed the new U.S. version, and spokesman Jeffrey Lancashire gamely defends its exponential growth.
Still, just how often does someone get sucked into a jet engine?
Lancashire said the aim of the new codes is to show consistency and uniformity within a category of injury -- "NOT whether every single injury/illness code will actually be used," he wrote in an email Tuesday.
No team was ever assigned to go back and eliminate entries "that would never happen or are extremely unlikely to happen," he added. The greater detail, he acknowledged, “has certainly led to some interesting injury codes.”
Which is why "Crushed by alligator: W58.03" is a code apart from "Crushed by crocodile: W58.13."