Medical Billing

# Identifying Combination Coding in light of ICD-10-CM Guidelines

- August 22, 2024
- Posted by Kristen Edwards

12 Dec

No wonder ICD-10 and CPT codes have been discussed over all these years as they were the main reason behind every reimbursement and transaction made at the payers’ and providers’ end. These codes are being updated with some new guidelines, declaring some new codes, rescheduled and redefining previous codes, introducing some combination coding for specific diseases, etc. each year.

These amendments are made federally by the Centers for Medicare and Medicaid-CMS. According to the recent updates, 363 new codes, 226 codes revisions, and 142 codes deletion had been made to ICD-10 coding this fiscal year. Apart from ICD-10 coding, understanding the use of diagnostic coding is also more difficult. But reducing and even eliminating these difficulties can be made easier if you know how to decode the complexity of the ICD codes. Plus, it is more than necessary to report and collect accurate codes for minimizing and even eradicating claim rejections.

## ICD-10 Combination Coding Explanation

northwestcareercollege.edu

Coders and billers at a medical facility use combination coding to elaborate different aspects related to one disease. According to the guidelines shared for coding and reporting from the federal, classify the use of combination code to elaborate;

- 2 diagnoses
- A symptom or diagnosis that is associated with a known complication
- A diagnosis along with an associated manifestation (secondary process).

When coders use ICD-10 combination coding, they specify definitive diagnosis and common symptoms associated with the disease. For instance,

- Ulcers for lower back pressure of stage II can be reported using two codes 707.03 for lower back and pressure ulcer and 707.02 for stage II pressure ulcer. However, for ICD-10 only without a combination code, one code represents one condition such as 132 Pressure ulcer stage 2 of the right lower back. Hence, ICD-10 combination codes for pressure ulcers include;
  - the location of the pressure ulcer (left or right)
  - pressure ulcer stage
  - the site of the pressure ulcer (upper or lower)

- For type 2 diabetes codes along with nonproliferative retinopathy with macular edema (mild), the distinctive codes would be required from ICD-9, including;
  - 52 Type 2 diabetes with ophthalmic manifestations
  - 04 Mild nonproliferative diabetic retinopathy
  - 07 Diabetic macular edema

Although these codes represent and are associated with the same condition when using ICD-10, only one code will be reported which is E11.321 Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema.

- Medical conditions occurred due to the consumption of medicament, drugs, or any biological substance, the coder will use ICD-10 combination coding which indicates the occurrence of the condition due to exposure to adverse effects, poisoning, underdosing or any other specific drug that had caused the effect. For instance, the accidental heroine code for overdose in ICD-9 would require two codes; for poisoning from heroin – 965.01 and accidental poisoning by heroin E850. However, in ICD-10, the entire encounter scenario will be reported with a combination code T40.1X1A for unintentional or accidental poisoning, and poisoning by heroin.

Further Examples of Combination Coding for ICD-10 include:

- I26.01 Septic pulmonary embolism with acute cor pulmonale
- K57.21 Diverticulitis of large intestine with perforation and abscess with bleeding
- E11.341 – Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy with macular edema
- E10.21 Type 1 diabetes mellitus with diabetic neuropathy
- I25.110 Atherosclerotic heart disease of the native coronary artery with unstable angina pectoris
- K80.67 Calculus of gallbladder and bile duct with acute and chronic cholecystitis with obstruction
- K71.51 Toxic liver disease with chronic active hepatitis with ascites

### Things to Remember

- When compared to ICD-9 codes, ICD-10 codes identify more specific information
- ICD-10 has more codes that can be used for combination coding
- According to the ICD-10 guidelines, when one ICD combination code can define all the associated symptoms and diagnoses, multiple codes for defining the same disease should not be used.
- Additional specificity of the diseases and diagnosis demand focused on hidden abstract information to choose from medical records that only a medical coding service provider would be able to monitor.
- ICD -10 codes require brief treatment documentation with detailed physician diagnoses.
- If there’s a combination code that specifies a disease but it lacks the information of provided treatment reporting, then a modifier or the related code should be applied as a secondary code.

Here are some examples where ICD-10 combination coding has expanded its claws;

### Common Symptoms and Conditions

- E10.21 Type 1 diabetes mellitus with diabetic nephropathy
- I25.110 Atherosclerotic heart disease of the native coronary artery with unstable angina pectoris
- K50.112 Crohn’s disease of the large intestine with intestinal obstruct

### Codes for External Causes and Poisoning

- T36.0x1D Poisoning by penicillins, accidental (unintentional), subsequent encounter
- T42.4x5A Adverse effect of benzodiazepines, initial encounter

Following are the examples where documentation needs details of the disease;

For Diabetes Mellitus:

- The affected body part or the system/organ must be identified
- The documented type of diabetes
- Reviewing categories for ICD-10 type 1 diabetes mellitus E10, Type 2 diabetes mellitus E11, and other diabetes mellitus E13 details will require documenting the combination codes.

For Hypertension:

Even if the relationship between heart disease and hypertension is casual, they must be documented as ‘hypertensive’ and ‘conditions cause hypertension’.

When it comes to severe kidney diseases, ICD-10 presumes a causal nexus relationship while identifying kidney diseases as chronic with hypertension as hypertensive chronic kidney diseases.

Where it is also necessary to document the stage of kidney disease.

For Atherosclerotic Coronary Artery Disease and Angina:

An assumption of the causal relationship between angina pectoris and atherosclerosis. For instance; ICD-10 code I25.110 (arteriosclerotic heart disease of the native coronary artery with unstable angina pectoris). While reporting, billers need to report two ICD-10 codes. If there’s something else that is diagnosed other than angina, it must be documented.

For Pressure Ulcers:

- The site must be documented where the ulcers are diagnosed
- The stage of the pressure ulcers should be indicated
- According to the new identification of the sacral region, the ulcer is added in ICD-10. For ICD-9, this unique region is already identified with a lower back code – 707.03

For Symptoms with a Combination Code:

- The known definitive diagnosis should be reported
- The symptoms for combination codes must be added
- While ICD-10 codes include combination codes, they can be used to identify common symptoms and definitive diagnosis of a disease.
- When the ICD-10 combination code is used, there is no need to add an additional coding for symptoms while mentioning combination codes for the identified disease.

Codes for an External Cause:

- Details and explanations about how the diagnosed injury happened even if it is stumbling or falling must be documented.
- Events that happened in sequential occurrence must be documented such as striking or stabbing with the knife or with sharp glass.
- The initial encounter and cause of the occurrence should be identified and documented.

## Ending Notes

The medical coding process must be covered by the experts in the field so they can be accurately coded and rejection and claim denials would minimally occur. However, coders should look for quality coding while billing for multiple diseases and symptoms while using combination coding, not for the quantity of the codes for efficient billing. Also have a look at this radiology coding.

A good time should be spent researching and reading the descriptions of codes provided in the guidelines to meet productivity standards. It is an essential need to keep in mind that the quality of data would be affected when you use multiple codes and modifiers to report a disease which can be documented by a single combination code. Hence, the practice affects revenue management and cause a delay in reimbursements.

Related Articles:

- How to use nephrology billing and Coding Guidelines
- Steps to Incorporate Cardiology Medical Billing Guidelines
- What is HCC Coding? How it affects Risk Adjustment Factors?

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