Tips for Coding Hypertension
The following information highlights tips for coding Hypertension, along with the combined codes for:
- Hypertension with Heart Disease
- Hypertension with Kidney Disease
- Hypertension with Heart and Kidney Disease
Also covered in this article are requirements for coding Screening and Follow-up issues.
The classification presumes a causal relationship between hypertension and heart involvement and between hypertension and kidney involvement, as the two conditions are linked by the term “with” in the Alphabetic Index. 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 hypertension and conditions not specifically linked by relational terms such as “with,” “associated with” or “due to” in the classification, provider documentation must link the conditions in order to code them as related.
HYPERTENSION WITH HEART DISEASE
Hypertension with heart conditions classified to I50.- or I51.4-I51.9, are assigned to a code from category I11, Hypertensive heart disease. Use an additional code from category I50, Heart failure, to identify the type of heart failure in those patients with heart failure.
The same heart conditions (I50.-, I51.4-I51.9) with hypertension are coded separately if the provider has specifically documented a different cause. Sequence according to the circumstances of the admission/encounter.
HYPERTENSIVE CHRONIC KIDNEY DISEASE
Assign codes from category I12, Hypertensive chronic kidney disease, when both hypertension and a condition classifiable to category N18, Chronic kidney disease (CKD), are present. CKD should not be coded as hypertensive if the physician has specifically documented a different cause. The appropriate code from category N18 should be used as a secondary code with a code from category I12 to identify the stage of chronic kidney disease. If a patient has hypertensive chronic kidney disease and acute renal failure, an additional code for the acute renal failure is required.
HYPERTENSIVE HEART AND CHRONIC KIDNEY DISEASE
Assign codes from combination category I13, Hypertensive heart and chronic kidney disease, when there is hypertension with both heart and kidney involvement. If heart failure is present, assign an additional code from category I50 to identify the type of heart failure. The appropriate code from category N18, Chronic kidney disease, should be used as a secondary code with a code from category I13 to identify the stage of chronic kidney disease. Codes in category I13, Hypertensive heart and chronic kidney disease, are combination codes that include hypertension, heart disease and chronic kidney disease. The Includes note at I13 specifies that the conditions included at I11 and I12 are included together in I13. If a patient has hypertension, heart disease and chronic kidney disease, then a code from I13 should be used, not individual codes for hypertension, heart disease and chronic kidney disease, or codes from I11 or I12. Secondary hypertension is due to an underlying condition and two codes are required: one to identify the underlying etiology and one from category I15 to identify the hypertension. Sequencing of codes is determined by the reason for admission/encounter.
- I15.0, Renovascular hypertension
- I15.1, Hypertension secondary to other renal disorders
- I15.2, Hypertension secondary to endocrine disorders
- I15.8, Other secondary hypertension
- I15.9, Secondary hypertension, unspecified
The five secondary hypertension codes require that you also code the underlying condition. ICD-10 typically permits either the underlying condition or the secondary hypertension code to be listed first depending on the reason for the patient encounter. The exception to this is I15.8, Other secondary hypertension. Because this is an “other” code, the “other” condition must be coded first.
As per the 2017 ICD-10 Guidelines, assign a code from category I16, Hypertensive crisis, for documented hypertensive urgency, hypertensive emergency or unspecified hypertensive crisis. Code also any identified hypertensive disease (I10-I15). The sequencing is based on the reason for the encounter.
Screening is the testing for disease or disease precursors in seemingly well individuals so that early detection and treatment can be provided for those who test positive for the disease (e.g., screening mammogram). Testing a person to rule out or confirm a suspected diagnosis because the patient has some sign or symptom is a diagnostic examination, not a screening. In these cases, the sign or symptom is used to explain the reason for the test.
A screening code may be a first-listed code if the reason for the visit is specifically the screening exam. It may also be used as an additional code if the screening is done during an office visit for other health problems. A screening code is not necessary if the screening is inherent to a routine examination, such as a pap smear done during a routine pelvic examination. Should a condition be discovered during the screening, the code for the condition may be assigned as an additional diagnosis. The Z code indicates that a screening exam is planned. After the exam, a procedure code is required to confirm that the screening was performed.
The screening Z codes/categories are:
- Z11 Encounter for screening for infectious and parasitic diseases
- Z12 Encounter for screening for malignant neoplasms
- Z13 Encounter for screening for other diseases and disorders
- Except: Z13.9 Encounter for screening, unspecified
- Z36 Encounter for antenatal screening for mother
The follow-up codes are used to explain continuing surveillance following completed treatment of a disease, condition, or injury. They imply that the condition has been fully treated and no longer exists. Follow -up codes may be used in conjunction with history codes to provide the full picture of the healed condition and its treatment. The follow-up code is sequenced first, followed by the history code. A follow-up code may be used to explain multiple visits. Should a condition be found to have recurred on the follow-up visit, then the diagnosis code for the condition should be assigned in place of the follow-up code.
Two of the follow-up Z code categories are:
- Z08 Encounter for follow-up examination after completed treatment for malignant neoplasm
- Z09 Encounter for follow-up examination after completed treatment for other than malignant neoplasm
Don’t forget to use an additional code to identify any acquired absence of organs (Z90.- ), and remember to read the Type 1 Excludes for aftercare following medical care (Z43 -Z49, Z51).