Coding tips for the top 10 diagnoses seen in CAHs

Details matter. Accurate medical coding for critical access hospitals (CAHs) and rural health facilities that is precise and follows the correct diagnostic sequences is critical for ensuring compliance, maximizing reimbursements, and avoiding denials.

Changing ICD-10 guidelines make coding for the broad spectrum of diagnoses seen in critical access and rural health facilities even more challenging. Consulting with experts can help.

Accurate documentation supports optimal medical coding for CAHs and rural health facilities. Here are the top 10 diagnoses commonly seen in critical access and rural health facilities, with corresponding coding tips:

Heart failure: Diagnosis codes for heart failure should be sequenced with the underlying cause of the heart failure listed first. If heart failure is due to hypertension, the hypertensive heart disease code should be listed before the specific heart failure code. Always follow the "code first" instructions provided in the ICD-10 coding guidelines for accurate sequencing.

• Example: Patient with hypertension and unspecified heart failure would be coded:
  I11.0- Hypertensive heart disease with heart failure
  I50.9- Heart failure, unspecified

Pneumonia: Accurate medical coding for pneumonia relies on clinical documentation that specifies the type of pneumonia or its causal agent. Provide sufficient detail, including the causative organism and any underlying conditions, to ensure the most specific coding possible. Also, identify severity of the condition.

• Example: Patient has pneumonia and the lab results confirm the pneumonia is due to staphylococcus aureus and is methicillin resistant. It would be coded:
  J15.212- Pneumonia due to methicillin-resistant staphylococcus aureus
  (When a combination code exists, you would code the combination code rather than coding for pneumonia and staphylococcus aureus separately.)
  
  

Acute myocardial infarction: A myocardial infarction (MI) is classified as acute if it occurs within four weeks of the initial symptom onset. If more than four weeks have passed, it's considered an old MI.

• Example: Patient presents for a routine checkup with a documented history of a myocardial infarction that occurred five years ago, currently asymptomatic with normal EKG findings. The MI would be coded:
  I25.2-Old myocardial infarction

This level of detail supports compliance and helps with medical reimbursement optimization.

Diabetes: Code for all types of diabetes a patient may have. For instance, if a patient has both diabetic retinopathy and diabetic nephropathy, code for both conditions. However, you cannot use a specified code and the unspecified E11.9 code together. This would cause a denial because it contradicts the other diabetes codes.

• Example: Patient presents with a diagnosis of type 2 diabetes mellitus and is currently experiencing moderate non-proliferative diabetic retinopathy with macular edema in both eyes, as well as diabetic nephropathy. It would be coded:
  E11.311- type 2 diabetes mellitus with unspecified diabetic retinopathy with macular edema
  E11.21- Type 2 diabetes mellitus with diabetic nephropathy

Precise documentation is essential for chronic care coding in rural health facilities.

Hypertension: ICD-10-CM classifies hypertension by type, as essential or primary (categories I10-I13), and secondary (category I15). Combination codes are used to report hypertension with associated conditions.

• Example: Patient presents with diagnosed hypertension and chronic kidney disease stage 3. It would be coded:
  I12.9- Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease
  N18.3- Chronic kidney disease, stage 3 unspecified
  
  

Arthritis: Make sure your documentation includes the following key details:

• Type of arthritis (osteoarthritis, rheumatoid arthritis, or other type)
• Laterality (which side of the body is affected) and the specific joints involved
• Prescribed  treatments and medications 
• Diagnostic findings, including results from imaging or laboratory tests
• Signs and symptoms experienced by the patient
• Objective findings, such as the presence of nodules or other physical manifestations

This level of detail leads to more accurate coding and better patient care.

• Example: Patient presents with significant pain, swelling, and stiffness in their left knee, with a medical history indicating a diagnosis of rheumatoid arthritis. It would be coded:
  M05.662- Rheumatoid arthritis of left knee with involvement of other organs and systems

Chronic hepatitis: Chronic hepatitis should be clearly documented to reflect its ongoing nature. Not specifying the condition as chronic can result in incomplete or inaccurate diagnosis codes.

• Example: Patient presents with ongoing elevated liver enzymes and fatigue, with no definitive cause identified through testing, leading to a diagnosis of chronic, unspecified hepatitis. It would be coded:
  B18.9- Chronic viral hepatitis, unspecified

Chronic kidney disease: Documentation should specify the stage of chronic kidney disease (CKD) and clearly link the condition to underlying causes such as diabetes and hypertension. ICD-10-CM guidelines allow CKD to be assumed as "due to" both hypertension and diabetes, even without explicitly linking it, unless the provider attributes CKD to a different condition. Additionally, CKD stage must be included in the code for accurate documentation and reporting.

• Example: Patient presents with a diagnosed case of chronic kidney disease stage 3b, with documented evidence of hypertension. It would be coded:
  I12.9- Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease
  N18.32- Chronic kidney disease, stage 3b
  
  

Depression: To code major depressive disorder accurately, documentation should include the following details:

• Symptoms must be present for at least two weeks, whether it is a single or recurrent episode
• Severity must  be coded as mild, moderate, severe without psychotic features, or severe with psychotic features
• Specify if the episode is in partial or full remission

If documentation lacks this level of specificity, the diagnosis can only support "major depression, unspecified" (F32.9).

• Example: Patient presents with symptoms of mild depression, including decreased energy, difficulty concentrating, and a persistent feeling of sadness, lasting for approximately three weeks with no prior history of depressive episodes. It would be coded:
  F32.0- Major depressive disorder, single episode, mild

Substance use: When a patient uses, abuses, or is dependent on the same substance, only one code should be assigned. The ICD-10-CM guidelines for assigning the code state:

• If both use and abuse are documented, assign the code for abuse
• If both abuse and dependence are documented, assign the code for dependence
• If use, abuse, and dependence are all documented, assign the code for dependence
• Example: Patient presents with a history of heavy alcohol consumption for several years, causing significant problems in their personal and professional life, including frequent blackouts, neglecting responsibilities due to drinking, and unsuccessful attempts to cut back on alcohol intake. It would be coded:
  F10.22 - Alcohol dependence with intoxication

Following these coding tips for critical access hospitals and rural health facilities improves care, ensures compliance, and reduces denials.    

NRHA adapted the above piece from Scribe EMR, a trusted NRHA partner, for publication within the Association’s Rural Health Voices blog.

About the author: Michelle Anderson is a leading expert in medical coding for federally qualified health centers and community health centers. As implementation manager at CodeEMR, she provides specialized implementation, training, and education to ensure compliance and optimize value. Michelle is a certified FQHC coding specialist, risk adjustment coder, medical compliance officer, professional medical auditor, and professional coder with ICD-10 expertise.