According to the AAPC (American Academy of Professional Coders), there are several reasons for a medical coder to only purchase volumes 1 and 2 of the ICD-9 coding books. From the AAPC website:
“If you work for a physician office or outpatient facility, you will only need volumes 1-2 of the ICD-9-CM manual. Hospitals and payers need the ICD-9-CM, volumes 1-3. Volume 3 is a system of procedural codes and it has been adopted for inpatient procedures reported by hospitals.”It can therefore be assumed that the procedural codes contained in the third volume are irrelevant to medical coders in offices and outpatient facilities. In case you find yourself wondering about the distinction between “inpatient” and “outpatient,” it really is just as simple as breaking down the words: a patient in considered an inpatient the day he or she is “formally admitted to the hospital with a doctor’s order” (as defined by the Medicare government website, link provided below).
A patient is considered an outpatient if he or she is receiving “emergency department services, observation services, outpatient surgery, lab tests, or X-rays, and the doctor hasn’t written an order to admit [him or her] to the hospital as an inpatient.”
The other reason provided by the AAPC is if a coder is preparing to take the CPC certification exam and cannot afford excess coding books. Volumes 1 and 2 of the ICD-9 coding books are the main book requirements for the AAPC’s certification exam; therefore, they can be considered the functional minimum to have as a prospective coder preparing for examination.
Click here for a list of the current year's medical coding books.
Medicare website link: http://www.medicare.gov/publications/pubs/pdf/11435.pdf