Basic Guidelines for Accurate Diagnosis Coding

Medical coding facilitates the billing process by bringing uniformity to the procedures through recognizable codes. Using standard diagnosis codes and procedure codes that are recognized by insurance companies, all medical practices, and relevant care related agencies, the medical coder will ensure that the insurance companies, commercial payer, or the Centers for Medicare and Medicaid (CMS) will recognize the billed item and how the diagnosis warrants that procedure, test, or treatment. Medical coders are responsible for ensuring proper Diagnosis Coding for each procedure billed to an insurance company. Although most claims billers do not actually code diagnosis, they are often responsible for choosing the correct code for each claim. This article provides tips for accurate coding as well as information regarding diagnosis codes on claims.

While there are many different techniques for coding based on the specialty of medical practice, there are some basic rules for coding that will always exist.

Only Code What Is Documented

In order to provide the most accurate diagnosis code, you may have to review several documents in the patient’s medical record. As a medical coder, it is not your job to diagnose the patient, but to code the decision made by doctors or other medical staff. In other words, you are not reading a list of symptoms to find the best code. You should be able to locate a diagnosis provided by a doctor and then pair that diagnosis with a numerical code.

Some Tips for Accurate Diagnosis Coding Include:

  • Locate the most specific, clear diagnosis. These can often be located on lab reports, history and physical reports, and physician’s notes.
  • Code to the highest level of specificity as possible.
  • Diagnosis codes can include up to five digits. Whenever possible, you should code to the full five digits.
  • Do not include an unconfirmed diagnosis for billing purposes.

Selecting Correct Codes for Claims Billing

By the time a claim for medical services reaches the billing department, a diagnosis should have been confirmed and coded in the medical records. Most facilities use technology that delivers a claim with the information included. If there are diagnosis codes in the medical records, they are systemically slotted into the claim. The problem with this is that it is also likely that a patient may have received multiple diagnoses during treatment. A claims biller must associate each line or service charge with the appropriate diagnosis in order to ensure claims payment.

For example, consider the Type 1 diabetes diagnosis above. It is possible that the patient sees a physician for the maintenance of his or her diabetes. It is also possible that the patient develops strep throat. The patient schedules an appointment to be treated for strep throat. The physician writes a prescription. In this case, two entities will generate a bill. The doctor’s office will bill for the visit and a pharmacy will issue a drug card claim for the medication. Although the patient does have diabetes, coding either claim with the diagnosis for diabetes will likely result in denial. Just because a patient has diabetes does not mean there is any reason to treat them for strep throat. In this case, the proper diagnosis would be strep throat, and diabetes does not even have to appear on the claim.

If the same patient were to be admitted to a hospital and treated for heart problems, the diabetic diagnosis may come into play as a supporting or secondary diagnosis on the claim. In some situations, treatment for a heart condition may be different for a patient with diabetes than for others. In these cases, adding the diabetic code on the claim supports the necessity of the billed treatment. The code would be secondary to the heart diagnosis, however.

Follow NCCI and MUE Guidelines

Medicare and Medicaid have some minor differences regarding coding regulations from other insurance payers. Coders must report units of service based on the National Correct Coding Initiative (NCCI) and Medically Unlikely Edits (MUEs). This is done to prevent reporting multiple services or procedures that should not be billed together because one service or procedure likely includes the other or because it is medically unlikely to be performed on the same patient on the same day.

Coding and choosing diagnosis codes for claims can be a complicated process. There are multiple resources available to assist coders, including various ICD-10 coding manuals. Insurance companies and federal payers also provide information about proper coding on their websites, and many software companies now provide programs that make accurate coding easier. Despite these resources, medical billing and coding still require attention to detail and the ability, the ability to think logically, and the intervention of a human in the claims process.

In fee-for-service medicine, physician services are paid based on the fee associated with the CPT or HCPCS code submitted on the claim form. The diagnosis code supports the medical necessity for the service and tells the payer why the service was performed. It can be the source of denial if it doesn’t show the medical necessity for the service performed.

Diagnostic and procedural codes are connected to nearly every system and business process in health plans and provider organizations, including reimbursement and claim processes. For smoother claim processing and reduced denials, equal attention to diagnosis coding is important. MedicalBillersandCoders (MBC) systematically connects diagnosis and procedural codes ensuring timely payments from insurance carriers. To know more about our medical coding and billing services you contact us at 888-357-3226/


Basic Rules and Guidelines for Medical Coding