Top 10 Must Follow coding Guidelines to Become Perfect in ICD 10 Coding

In medical coding, both CPT and ICD 10 codes have specific coding guidelines.  The ICD 10 coding guidelines are given in the first pages of the ICD 10 code book, while CPT coding guidelines are given in front of each chapter in the CPT code book. Coding guidelines are always important in all places, wherever you are working. Even coding guidelines are important for preparation of medical coding certification exams.

If you ask medical coders which one is difficult to learn between ICD-10 and CPT codes, around 85% will say ICD 10 codes. You can become perfect in procedure coding or CPT codes in few months but to get perfect with ICD 10 codes, you need at least a year. Yes, after one year of ICD 10 coding you will improve in your coding skills and code any medical report confidently with diagnosis codes.

Since now we are using ICD 10 codes, which are more specific compared to ICD 9 codes, we will need to follow each specific coding guideline to become perfect with ICD 10 codes. I have filtered the top 10 ICD 10 coding guidelines which can help you to boost your knowledge in diagnosis coding. Simultaneously, this will also help you to prepare you from medical coding certification exams without any professional training.

1. Code only specific ICD 10 codes

Specificity is very important in diagnosis coding. ICD 10 codes have the most specific codes in each chapter of ICD 10 codebook. For example, the injury codes which have different 7th character (A,D & S) depending on the treatment for the injury itself shows the specificity of the ICD 10 codes.

Specificity matters when their is a specific and non-specific ICD 10 code in a medical report. For example, a patient comes with a abdominal pain to the physician and after examination through complete ultrasound of abdomen (CPT code 76700), the physician finds nothing but specifies the pain in right upper quadrant of the abdomen. Hence, here the medical coder can report the chief complaint (CC) as Abdominal pain (R10.9) but the final diagnosis should be right upper quadrant abdominal pain (R10.11). Do not report together unspecified abdominal pain (R10.9) with a specified abdominal pain (R10.11). Only report the specific sign & symptom or diseases or disorder.

2. Code only the most severe disease or disorder

This is a very easy guideline but followed very rarely by medical coders. In this guidelines severity is very important to understand. In simple language, do not code any sign and symptom which are a part of the disease or disorder. Sign and symptoms are a part of disease, hence if you are reporting a disease or disorder, the sign and symptoms are automatically get included in the main disease ICD 10 code.

For example, if a patient has cough (R05) and the physician finds a pneumonia after examination through Chest X-ray, the coders should only report Pneumonia (J18.9) as final diagnosis. Since, cough is a symptom of Pneumonia, hence it should not be reported with the main disease Pneumonia.

Similarly, if a patient has abdominal pain (R10.9) and the final diagnosis is colon diverticulosis (K57.30), then only colon diverticulosis should be reported, abdominal pain will be a symptom for diverticulosis.

Hence, Specificity and Severity are important terms to follow in ICD 10 diagnosis coding.

3. Code only Encounter Codes as Primary Diagnosis

In ICD 10 we have a list of Primary and Secondary diagnosis. As per ICD 10 coding guidelines, the Primary diagnosis should be always be reported as Primary diagnosis, while secondary diagnosis should be reported as secondary diagnosis.

All Encounter Z codes should be always reported as primary diagnosis whenever they are present in medical report. Only exception is when a medical report has two or more encounter Z codes, all should be reported, keeping any one of the encounter codes as primary diagnosis followed by other encounter Z codes.

For example Z12.11: Encounter for screening for malignant neoplasm of the colon, should be reported as primary diagnosis, similarly Encounter for antineoplastic chemotherapy Z15.11 should be reported as primary diagnosis. If both encounters are present, report any one as primary followed by other encounter ICD 10 codes.

4. Use Aftercare and Follow up code cautiously

Z codes should be used very carefully while coding aftercare and follow up codes. Many medical coders are still not aware of difference between aftercare and follow up ICD 10 codes.

Aftercare Z codes should be used till the diagnosis is still in healing phase. For example an aftercare for other orthopedic care , Z47.89 should be used when the fracture is under healing phase.

Follow up Z codes should be used only when the diagnosis has been completely healed. For example, the malignant neoplasm is completed removed and for any follow up visit, code Z08 as primary diagnosis followed by personal history of malignant neoplasm.

This is the actual coding guidelines for coding aftercare and followup Z codes in ICD 10.

5.Use Secondary codes whenever required by Primary diagnosis

Secondary codes are very important because it gives more specific information about some of the primary diagnosis. The one best example is we have just seen in the above guideline for coding follow up Z codes. While coding follow up Z codes, we have to code the personal history of disease/malignant neoplasm with the follow up ICD 10 Z code to give more specific information.

Moreover, their are many status Z codes which must be always used as Secondary diagnosis. 

6.Never use Normal and complication codes together in Pregnancy chapter

In pregnancy chapter, one of the most important point to remember of differentiating between normal and pregnancy complication ICD 10 codes. A normal Pregnancy ICD 10 codes should never be used along with a complication pregnancy diagnosis codes.

For example, if we are coding Z34.00, Encounter for supervision of normal first pregnancy, unspecified trimester, we are not supposed to report a pregnancy complication OXX.XXX code with them. The simple reason is that a normal pregnancy will not have any complications and hence both normal and complication codes cannot be reported together as per ICD 10 coding guidelines.

Another important coding guideline is to report Z3A category codes for weeks of gestation as secondary dx with a pregnancy complication codes. The Z3A should be only reported with the pregnancy complication codes ranging from O09-O9A as per ICD 10 coding guidelines.

7.Coding Active and Subsequent encounters in Injury codes

The ICD 10 codes for injury have very specific diagnosis codes. The Injury codes should have different 7th character depending on the active treatment or not. The active treatment should of injury should be reported with “A” initial encounter. For subsequent encounter report “D” as 7th character for injury ICD 10 codes. For sequela used directly S as 7th character for injury codes.

To know more about injury coding do refer the below post

Use of Active and Subsequent injury ICD 10 codes

When to use code Fracture codes Perfectly

8. Coding for Acute and Chronic ICD 10 codes

ICD 10 have specific coding guidelines to report both acute and chronic condition together. As per the coding guidelines whenever both acute and chronic condition occurs, the coders need to report both chronic and acute condition together with sequencing the acute code first. Acute and chronic conditions are defined as below.

Acute  means having rapid onset, severe symptoms, and a short course

Chronic means of long duration; denotes a disease showing little change or slow progression

9. ICD 10 Coding for suspected and Ruled out condition

In many scenarios, the condition may be suspected or ruled out as per the documentation. The medical report will not have any confirm diagnosis. As per the outpatient ICD 10 coding guidelines, only the confirmed diagnosis should be reported. Suspected, consistent, compatible etc. are not considered as confirmed diagnosis, hence should not be reported for outpatient coding.

For suspected and rule out condition, the medical coders have to report Z03.89, Encounter for medical observation for suspected diseases and conditions ruled out as primary diagnosis, followed by any other incidental findings.

10. Coding Primary and Secondary Neoplasm perfectly

Many medical coders are not still perfect with neoplasm coding. The medical report documentation should be clear for coding primary and secondary malignant neoplasm. To code neoplasm perfectly, the medical coders need to understand difference between metastatic and metastasis.

Metastasis neoplasm should be always reported as secondary malignant neoplasm always.

Metastatic neoplasm should be thoroughly checked in the medical report to report it as primary or secondary neoplasm. For example, if the documentation says only metastatic lung cancer then we can report primary lung neoplasm, but if it says metastatic to lung cancer, then it should be reported as secondary malignant neoplasm of lung.

But if still coders have doubt in coding the neoplasm you can directly query the provider for coding such scenarios, then only take any decision for coding.

Conclusion

Finally these ICD 10 coding guidelines will be very useful for both certified and Non-certified medical coders. Non-certified medical coders can get lot of information for preparation of medical coding certification exams through these coding guidelines. These Coding guidelines are followed by most of the payers. Hope all these information will help coders to gain more knowledge about diagnosis coding.