ICD-10 Codes for Hypertension (I10–I1A)
Most hypertension is a single code — I10. But the moment the heart or kidneys are involved, ICD-10 switches to combination codes (I11–I13) that assume the link. Getting that switch right — and knowing the kidney rule is different from the heart rule — is where these claims are won or lost.
The hypertension categories
ICD-10-CM organizes hypertension by what other organ it has started to affect. Start with whether the heart or kidneys are involved — that decides the category.
| Category | What it covers |
|---|---|
| I10 | Essential (primary) hypertension — the default when no heart or kidney involvement is documented |
| I11 | Hypertensive heart disease (with or without heart failure) |
| I12 | Hypertensive chronic kidney disease |
| I13 | Hypertensive heart and chronic kidney disease (both involved) |
| I15 | Secondary hypertension (renovascular, endocrine, or other identified cause) |
| I16 | Hypertensive crisis — urgency or emergency |
| I1A | Other hypertension — holds I1A.0, resistant hypertension, which is coded in addition to the hypertension type |
One thing that trips up coders from the ICD-9 era: ICD-10 has no “controlled/uncontrolled” hypertension codes (ICD-9 didn't either), and the old ICD-9 “benign” vs. “malignant” distinction was dropped.
The codes you'll use most
| Code | Description |
|---|---|
| I10 | Essential (primary) hypertension |
| I11.0 | Hypertensive heart disease with heart failure |
| I11.9 | Hypertensive heart disease without heart failure |
| I12.9 | Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease |
| I12.0 | Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease |
| I13.0 | Hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease |
| I16.0 | Hypertensive urgency |
| I16.1 | Hypertensive emergency |
Need a code that isn't here? Search the full I10–I1A family in the lookup tool.
How to choose the right hypertension code
1. Is the heart involved?
If the record documents a qualifying heart condition with hypertension — heart failure (I50.-) or certain conditions in I51.- such as cardiomegaly or myocardial degeneration — use I11, not I10. Under the “with” convention, ICD-10 assumes the hypertension caused that heart condition, so no explicit causal statement is needed. When heart failure is present (I11.0), also code its type from I50.-. Important exception: coronary artery disease / atherosclerosis (I25.-) is not presumed related to hypertension — code it separately unless the provider documents a link.
2. Are the kidneys involved?
This one is close to automatic. Hypertension and chronic kidney disease are coded as a combination (I12) by default — ICD-10 presumes they're related, with no causal statement needed — unless the provider documents that the CKD is unrelated to the hypertension, in which case code I10 and the N18.- stage separately. When I12 applies, pick the subcode by CKD stage, and also code the stage itself from N18.-.
3. Are both heart and kidney involved?
Use I13, which combines both. Choose the subcode by whether heart failure is present and by the CKD stage, and still add the I50.- and N18.- codes for specificity.
4. Is it a hypertensive crisis?
Code I16.0 for urgency or I16.1 for emergency, and also code any identified hypertensive disease — I10–I15, plus I1A.0 when resistant hypertension is documented. The guidelines base the sequencing on the reason for the encounter. I16 was added to ICD-10-CM in 2017, so older references may not show it.
5. Is it documented as resistant?
Resistant hypertension — blood pressure that stays above goal despite antihypertensive medications — has its own code, I1A.0. Assign it as an additional code when the provider documents apparent treatment resistant, treatment resistant, or true resistant hypertension, and sequence the code for the specific type of hypertension first, if known (for example I10, or I15.- for secondary hypertension). “Uncontrolled” is not a synonym: per the guidelines, uncontrolled hypertension still codes to I10–I15, and I1A.0 needs the provider's “resistant” wording.
Common hypertension coding mistakes
- Staying on I10 when the heart or kidneys are involved. Once heart disease/failure or CKD is documented, the code moves to I11, I12, or I13. Reporting I10 alone understates the condition.
- Forgetting the paired code. I11.0 needs the
I50.-heart-failure code; I12 and I13 need theN18.-CKD stage. The combination code alone isn't complete. - Hunting for “benign,” “malignant,” or “uncontrolled.” None exist in ICD-10. Document essential vs. secondary, organ involvement, and any crisis instead.
- Coding secondary hypertension as I10. When an underlying cause is documented (renal artery stenosis, an endocrine disorder), use
I15.-— and per the guidelines, sequence the codes per the reason for the encounter.
A worked example
I13.0N18.4I50.22Both the heart and kidneys are involved, so the code comes from I13 — not I11 or I12. I13.0 is the right subcode (heart failure present, with stage 1–4 CKD). Then add what it doesn't capture on its own: N18.4 for the CKD stage and I50.22 for the chronic systolic heart-failure type.
Don't overlook secondary hypertension
Most hypertension is essential (primary), but when the documentation points to an identifiable cause — renal artery stenosis, an endocrine disorder such as hyperaldosteronism, or a medication — it's secondary hypertension, coded from I15.-. ICD-10 asks you to code both the secondary hypertension and its underlying condition, sequenced according to the reason for the encounter. Reaching for I10 by reflex on a patient whose hypertension has a documented cause misses that specificity — and, in some payer models, the clinical picture that justifies the workup.
What the note needs to document
- Whether it's essential (primary) or secondary (and, if secondary, the underlying cause)
- Any heart involvement, and the type of heart failure if present
- Any chronic kidney disease, and its stage
- Hypertensive urgency or emergency if the visit involves a crisis
Frequently asked questions
For uncomplicated high blood pressure, the code is I10, essential (primary) hypertension. If the heart or kidneys are involved, you move to a combination code: I11 (hypertensive heart disease), I12 (hypertensive chronic kidney disease), or I13 (both).
No. ICD-10-CM has no “controlled,” “uncontrolled,” “benign,” or “malignant” hypertension codes. (ICD-9 had a benign/malignant distinction, which was dropped; it never had controlled/uncontrolled codes.) Document the type (essential vs. secondary), any organ involvement, and any hypertensive crisis (I16) instead.
Use a combination code from I12 (or I13 if the heart is also involved), and also code the CKD stage from N18.-. ICD-10 presumes hypertension and CKD are related, so the combination is used even without a documented causal statement — unless the provider documents the CKD is unrelated, in which case code I10 and N18.- separately.
Use I11.0 (hypertensive heart disease with heart failure), and also assign a code from I50.- to identify the type of heart failure. If chronic kidney disease is also present, use I13 instead.
I16.0 (urgency) is a severe blood-pressure elevation without acute target-organ damage; I16.1 (emergency) is a severe elevation with acute target-organ damage. Also code the underlying hypertension type.