What is Medical Coding...

Medical Coding is the process of converting healthcare diagnoses, procedures, medical supplies/services, and equipment into alphanumeric codes. The diagnoses,procedures and services provided are abstracted from medical records that may either be paper or EHR (Electronic Health Record).

ICD (International Classification of Diseases) guidelines (set of rules to follow while assigning codes) are used to abstract the diagnoses from the medical records. These guidelines are developed by CMS (Centers for Medicare and Medicaid

Services and NCHS (National Center for Health Statistics, who are part of the U.S. Federal Government’s Department of Health and Human Services.

ICD guidelines have been approved by the four organizations that make up the Cooperating Parties: The American Hospital Association, American Health Information Management Association, CMS, and NCHS.

The ICD guideline are revised annually and the updated guidelines will be published and will become effective from 1st October of every year.

More than 100 countries are using ICD guidelines to process the medical codes. Few countries have modified the guidelines according to their local Healthcare System requirements. ICD 10-CM is used by The USA, Canada and few Middle East  countries whereas ICD 10-AM is used in Australia, New Zealand, Singapore, Saudi Arabia, Qatar, Kuwait etc. UK has got their own modification of ICD guidelines.

Medical Terms

Medical terminology contain 3 main parts. If you are aware of these 3 it will be easy for you to understand simple to complex medical/clinical terms.

                    Root word GASTR | ITIS suffix

                           Related to               inflammation
                             stomach



                              Prefix: The term before the root word.

                              Root word: The main term you are pointing to/related to organs/systems/parts/procedures.

                              Suffix: The term at the end of root word.

                                     ab-                      away from (abduction)

                                     abdomin/o      abdomen


A few of the frequently used medical terms in In-patient DRG coding......

Anti-inflammatory: Reduces swelling, pain, and soreness (such as ibuprofen or naproxen)

Body Mass Index (BMI): Body fat measurement based on height and weight

Biopsy: A tissue sample for testing purposes

Comminuted fracture: Broken bone that shatters into many pieces

Hypotension: Low blood pressure

Hypertension: High blood pressure

Lesion: Wound, sore, or cut

Benign: Non-cancerous

Malignant: Cancerous

Noninvasive: Non-surgical (No instrument to enter the body)

Inpatient: Plan to stay overnight for one or more days

In remission: Disease is not getting worse; not to be confused with being cured

Membrane: Thin layer of tissue that serves as a covering or lining or connection between two structures

Acute: Suddenly happening, but shorter duration (e.g., acute illness)

Angina: Pain in the chest related to the heart that comes and goes

Cellulitis: Inflamed or infected tissue beneath the skin

Compound fracture: Broken bone that protrudes through the skin

Epidermis: Outermost layer of skin

Edema: Swelling

Embolism: Blood clot

Sutures: Stitches

Polyp: Mass or growth of thin tissue

Origin of DRGs

The first functional set of DRGs was developed in the early 1970s. 

The process of forming the original DRGs was begun by dividing all possible principal diagnoses into multiple mutually exclusive PDX categories referred to as Major Diagnostic Categories (MDCs). 

The MDCs were formed by expert panels as the first step toward ensuring that the DRGs would be clinically coherent. The diagnoses in each MDC correspond to a single Organ System

or etiology and in general, are associated with a particular medical specialty. Thus, in order to maintain the requirement of clinical coherence, no final DRG could contain patients in different MDCs.

What is IP-DRG Coding

The Diagnosis Related Group (DRG):

A patient classification system, which provides a means of relating the type of patients a hospital treats to the costs incurred by the hospital.

There are currently three major versions of the DRG in use: Basic DRGs, All Patient DRGs, and All Patient Refined DRGs.

The basic DRGs are used by CMS for hospital payment for Medicare beneficiaries.

The All Patient DRGs (AP-DRGs) are an expansion of the basic DRGs to be more representative of non-Medicare populations such as pediatric patients.

The All Patient Refined DRGs (APR-DRG) incorporate SOI into the AP-DRGs.



DRGs will be affected by Principle Diagnosis, MCC (Major complications or comorbidities), CC (Complications or comorbidities), Age, Gender, Principle Procedure etc.

Principle Diagnosis: Also called as PDx, the condition established after study to be chiefly responsible for occasioning the ADMISSION of the patient to the HOSPITAL for care.

                           In brief Principal Diagnosis represents the main cause of admission of a patient to the hospital for treatment.


                Complication: Complication is a condition that arises during the hospital stay that prolongs                  the length of stay of a patient.

                 Co-morbidity: Pre-existing condition that affects the treatment received and/or prolongs                       the length of stay.

     MCC: Also called as Major complications or comorbidities. Ex: Acute CVA / Stroke / Cerebral Infarct or Hemorrhage, Acute MI, Pulmonary Embolism, Decubitus Ulcer, Diabetic Ketoacidosis, Encephalopathy – Metabolic, Toxic, ESRD, GI Disorder w/ Hemorrhage, Malnutrition, Pneumonia, Respiratory Failure, Sepsis, Severe Sepsis, Septic Schock etc. (Please follow CMS guidelines for annual update of MCC list)

         CC: Also called as Complications or comorbidities. Ex: ABLA (Acute blood loss anemia), Acidosis, Ascites, Cachexia, Cardiomyopathy (non-ischemic), Cellulitis, Crohn’s Disease, Diverticulitis, Esophagitis, Hemiplegia, Hypernatremia / Hyponatremia, Ileus, Pyelonephritis, UTI etc. (Please follow CMS guidelines for annual update of MCC list)