As we’ve discussed, medical coding is the process of assigning standardized numbers to diagnoses/diseases, causes of death, and inpatient and outpatient medical procedures. The primary reason for medical coding is to ensure consistent classification and billing, as it enables physicians, medical centers, and third-party payers to “talk” in the same language.
So where do these codes come from? There are four major “code sets” in the medical coding world, each with a different use:
- International Statistical Classification of Diseases and Related Health Problems (ICD), maintained by the World Health Organization
- International Statistical Classification of Diseases and Related Health Problems, Clinical Modification (ICD-CM), maintained by the Centers for Medicare and Medicaid Services and the National Center for Health Statistics
- Healthcare Common Procedure Coding System (HCPCS), maintained by the Centers for Medicare and Medicaid Services
- Current Procedural Terminology (CPT), maintained by the American Medical Association
Here’s how they fit together:
ICD-9: The ninth revision of the ICD code set, ICD-9 was used to classify mortality (death) in the U.S. until Jan. 1, 1999, and is now obsolete (replaced by ICD-10).
ICD-9-CM: The ninth revision of the ICD code set with “clinical modifications,” ICD-9-CM is used today in the U.S. to classify morbidity (diagnoses/diseases) and inpatient medical procedures. It consists of three volumes: volume one (tabular listing of diagnosis codes), volume two (index of diagnosis codes), and volume three (procedure codes). An ICD-9-CM code has between three and five characters, such as 560, 553.3, or 560.81.
ICD-10: The 10th revision of the ICD code set, ICD-10 replaced ICD-9 for classifying mortality in the U.S. as of Jan. 1, 1999.
ICD-10-CM: The 10th revision of the ICD code set with “clinical modifications,” ICD-10-CM is an expanded and revised version of ICD-9-CM, and will be put into use in the U.S. as of Oct. 1, 2013, to classify morbidity. An ICD-10-CM code has between three and seven digits; examples are M05.339 and S26.020D.
When you hear rumblings that medical centers are anxious about planned ICD changes, it’s this forthcoming implementation of ICD-10-CM across the U.S. that’s causing the angst.
HCPCS: A two-level code set used to classify outpatient medical procedures. Level one consists of CPT codes (see below), while level two classifies non-physician services and supplies, such as ambulance transportation and medical equipment.
CPT: Serves as HCPCS level one and is used in the U.S. today to classify all outpatient medical and surgical procedures (ICD-9-CM volume three is used to classify inpatient procedures). A CPT code has five digits, such as 39520 or 00756.
A subset of CPT codes, called evaluation and management (E&M) codes, are used to classify non-surgical physician visits/consultations.
Put another way, in the U.S. today …
- ICD-9-CM volumes one and two are used to classify morbidity
- ICD-9-CM volume three is used to classify inpatient hospital procedures
- ICD-10 is used to classify mortality
- HCPCS level one (CPT) is used to classify outpatient procedures
- HCPCS level two is used to classify medical equipment, supplies, and drugs
The intersection of medical coding and health care information technology — pmFAQtory’s field — is pretty clear-cut. For humans, sorting through various code sets and tens of thousands of individual medical codes, while at the same time ensuring compliance with payer regulations, is about as much fun as doing taxes by hand.
That’s why numerous technological solutions have surfaced to help medical centers more efficiently assign codes and ensure accuracy. pmFAQtory specializes in guiding health care organizations as they implement these systems, which sit within a complex health IT landscape. We’ll examine that landscape in more detail in the next few weeks.