Biomedical Engineering and Design

Information specific to BME and BME/CBID design teams.

Codes and Classifications

Health care reimbursement is complex.


1. Overview of some codes and how they're used for payments (as of July 2019)

  • ICD-10-CM (Clinical Modification) = diagnoses
  • ICD-10-PCS (Procedure Coding System) = procedures
  • CPT (Current Procedural Terminology) = part of HCPCS
  • HCPCS (Healthcare Common Procedural Coding System) : Level I is the CPT, and Level II is mainly for identifying products, supplies, and services that are NOT included in the CPT, such as ambulance services; drugs; devices; and "durable medical equipment, prosthetics, orthotics, and supplies" (DMEPOS), used in outpatient settings such as hospital outpatient departments, physicians' offices, and patients' homes

ICD (International Classification of Diseases) is maintained by the World Health Organization, and is international.

CPT (Current Procedural Terminology) is maintained by the American Medical Association, and is United States only.

2. Please read the Health Care Reimbursement guide, especially the Reimbursement Toolkit page, which also has information about "Classification and Coding Systems":

CPT -- Current Procedural Terminology
  • The American Medical Association produces this annual list to classify and report medical services and procedures.
    --- Overview of what CPT codes are, and descriptions of CPT categories I, II, and III
    --- Look up CPT codes for free on the AMA website (create a free account, and click "agree" for the terms)
    --- You can also look around the web for CPT codes, but please add   to your search (so that you get U.S. government results), and/or get *several* results from the web, so that you can verify that the code you found is correct
  • Public and private health insurance programs depend on CPT codes to describe medical, surgical, and diagnostic services, to manage reimbursements, and to facilitate reliable nationwide communication among physicians, other healthcare providers, patients, and third parties.


HCPCS -- Healthcare Common Procedure Coding System

The HCPCS has two levels:
  1. CPT (whose information is on the previous tab)
  2. DMEPOS -- For "products, supplies, and services NOT included in the CPT codes, such as ambulance services and durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) when used outside a physician's office."
    This system was created to identify services, supplies, and equipment that are not included in the CPT but which *are* covered by Medicare and other insurers.
Here is the DMEPOS fee schedule that you can search
  • Unlike the CPT and ICD, you *cannot* search this with keywords, but only with the DMEPOS code itself
  • The easiest way to find those is by searching the open web, but look at more than one source to make sure you've found the correct code

HCUP (Healthcare Costs and Utilization Project) and HCUPnet

  • The Healthcare Cost and Utilization Project (HCUP) collects the data from "State data organizations, hospital associations, private data organizations, and the Federal government," and "includes the largest collection of longitudinal hospital care data in the United States," beginning in 1988. HCUP is run by the Agency for Healthcare Research and Quality (AHRQ).
  • The databases within HCUPnet (middle column) help research on health policy issues such as "cost and quality of health services, medical practice patterns, access to health care programs, and outcomes of treatments at the national, State, and local market levels"

National statistics -- updated annually
State statistics -- updated as new state data are processed
Note: There is at least an 18-month lag between the end of the calendar year and the availability of the Nationwide Inpatient Sample (NIS)


  1. On the HCUPnet page, choose "Create a new analysis"
  2. "Inpatient" will get you the most information
  3. NOTE:  The numbers in "Emergency Department" and in "Ambulatory Surgery" only represent patients from about 2/3 of U.S. hospitals. Therefore, multiply the numbers you get by 3/2.
  4. For classification, note that there are several different ones for ICD-10, and you can mouse over them for definitions:

    Note: "Trends" has data only through 2014 (and uses ICD-9).
  5. After you have chosen which kind of ICD or other kind of code to use, you will see "select codes." This is their built-in tool for finding ICD-10 codes. but no other kinds. (You can also use this to find ICD-10 codes, and then put the basic part of the code; e.g., K27, to search.)

6. If you have more than one code, "combine all codes"

7. Create analysis. (Understanding the results can be difficult sometimes. This methodology page is long, but gives more detail, definitions, and other info.)

Refining Your Results

The blue navigation bar on the left includes several ways to focus your results, including:

  • results by patient or hospital characteristics
  • settings of care, geography, and year of analysis
  • all-listed vs. principal diagnosis or procedure (remember that principle will not include patients who had the diagnosis as a secondary or tertiary problem, so think about whether you want ONLY that main diagnosis, or ALL patients who had it, no matter what else they had).

Your results can also be graphed and exported (click SUBMIT at the bottom to make your changes).

Note: Some selections on the blue navigation bar might be greyed out; this could be because of the database type, data year (after 2015, when ICD-10-CM/PCS codes were introduced); principal versus all-listed diagnosis (procedure); or other reason. 

To clear your selections, either go back to the home page (this will clear everything), or change your selections on the blue navigation bar, and click SUBMIT again.

HCUPnet Tutorials
-- Click orange button on top right of the HCUPnet page to see this:


ICD - International Classification of Disease 

ICD-10 became the official version on October 1, 2015.

  • The ICD is used to code signs, symptoms, injuries, diseases, and conditions
  • It standardizes reporting of illness, death, and medical procedures; and the classification of diseases and other health problems recorded on many types of health and vital records, such as death certificates
  • This allows the compilation of national mortality and morbidity statistics by WHO Member States, which is also essential for compiling of statistical info about diseases in a format that allows international comparison of those data. (The ICD was originally created by the World Health Organization (WHO), and is now maintained by the Centers for Medicare & Medicaid Services (CMS).
  •  Here are the ICD search tools from the WHO and from the CDC



  • DynaMed Plus also gives ICD-10 codes; search the medical condition and you'll see "ICD Codes" on the left
  • Ignore "GEMS" (General Equivalence Mappings) if you see it mentioned; that's the translation to and from ICD-9 and ICD-10 codes, and 2018 was the last one


ICF -- International Classification of Functioning, Disability, and Health

This classification was created by the World Health Organization (WHO) and approved in 2001.

Its purpose is to provide a "framework for measuring health and disability at both individual and population levels."

The WHO page about the ICF includes:

(Remember that this framework is only one piece of a complicated landscape!)


For more codes and information, see the Reimbursement Toolkit page of the Health Care Reimbursement guide.