Improving Coding for Hypertension Associated with Diabetes

Basics of Coding for Hypertension Associated with Diabetes

Most coders are still confused about which is the correct code for hypertension associated with diabetes. If you look carefully, hypertension is not listed as a specified complication. Hypertension is considered a circulatory complication so the correct code could be E11.59 rather than the more unspecified code of E11. 69 (other specified complication). We can also refer, an audit report by Humana where it was indicated that diabetes and hypertension have an assumed relationship and it should be coded as E11.59 (for type 2 diabetic.)

Coding Hypertension and Diabetes Separately

Some coders mention code as I10 for hypertension and E11.9 for diabetes. As diabetes is not always associated with hypertension, one should read provider documentation clearly and code it accordingly. Diabetes is documented and supported with a complication of Hypertension. You can also refer few guidelines for this approach. If the provider has only documented ‘diabetes with hypertension’, then you would not presume a causal relationship between the two because the two terms ‘diabetes’ and ‘hypertension’ as these are not linked in ICD-10 by the term ‘with’.

If the provider has specifically documented that the hypertension was caused by diabetes, then you would code hypertension as a circulatory complication. Only the terms listed in the index under ‘diabetes with’ should be coded as a complication with specific documentation linking them.

The word ‘with’ or ‘in’ should be interpreted to mean ‘associated with’ or ‘due to’ when it appears in a code title, the alphabetic index, or an instructional note in the tabular list. The classification presumes a causal relationship between the two conditions linked by these terms in the alphabetic index or tabular list. These conditions should be coded as related even in the absence of provider documentation explicitly linking them unless the documentation clearly states the conditions are unrelated. For conditions not specifically linked by these relational terms in the classification or when a guideline requires that a linkage between two conditions be explicitly documented, provider documentation must link the conditions in order to code them as related.

For more information, you can also refer to Coding Clinic 4th QTR 2017 and 2nd 2018 (AHIMA document). In order to assume a ‘with’ connection, the specific condition must be listed in the alphabetic index or tabular list. ‘NEC conditions’ are not assumed to be related. In our current assumption, hypertension is not specifically listed as an assumed diabetic complication so the code for diabetes with other circulatory conditions should not be assigned.

The exception to this would be if the documentation specifically makes the connection, hypertension due to diabetes. Diabetes and hypertension are not presumed to be related unless the provider specifically documents that it is. An example of assuming the connection would be if the patient is diagnosed with both Diabetes and Retinopathy. In that case, the connection is assumed and the appropriate combination code would be assigned.

Diagnosis Coding Example

Let’s refer to one coding example from JustCoding on reporting diabetes, Chronic Kidney Disease (CKD), and Hypertension (HTN) in ICD-10-CM.

Example: We had a patient with Type 2 diabetes who was admitted for hypoglycemia with metabolic encephalopathy. The patient also had stage 2 chronic kidney disease (CKD) and a diagnosis of hypertension (HTN). Which ICD-10-CM codes should we assign for this patient’s encounter?

ICD-10-CM assumes a cause-and-effect relationship between CKD and HTN, as well as CKD and diabetes. CKD is most likely related to both HTN and diabetes when all three conditions are present. High blood pressure and high blood sugar in the blood vessels can lead to the deterioration of the vessels, which can then cause damage to the kidneys. CKD should not be assigned as hypertensive if the provider’s documentation specifies that the CKD is not related to hypertension. Always query if the physician’s documentation seems unclear, but based on the information given, I would report the following ICD-10-CM codes for this patient’s encounter:

  • 649, Type 2 diabetes mellitus with hypoglycemia without coma
  • 41, metabolic encephalopathy
  • 22, Type 2 diabetes mellitus with diabetic CKD
  • 9, hypertensive CKD with stage 1 through 4 CKD, or unspecified CKD
  • 2, CKD, stage 2 (mild)

Medical Billers and Coders (MBC) is a leading medical billing company providing complete medical billing and coding services. You can refer payer specific coding guidelines for accurately coding for hypertension associated with diabetes. In case any assistance needed in medical billing and coding for your practice, email us at: or call us: 888-357-3226.