Hypertension with CKD or heart failure: I11, I12 or I13?

Does the provider have to link hypertension to the heart failure or CKD?

No. Section I.C.9.a of the FY2027 Official Guidelines builds the relationship into the classification:

“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.”

The “with” sits under the Index main term Hypertension, hypertensive. The subterm with › heart failure leads to I11.0; with › kidney involvement is a cross-reference to Hypertension › kidney, which leads to I12.9 or, for stage 5 CKD or ESRD, I12.0. The subterm cardiorenal carries the I13- codes. A problem list reading “hypertension, CHF, CKD stage 3b” therefore supports a combination code as written. The presumption covers heart and kidney involvement only; other conditions need the provider to link them.

Which combination code applies: I11, I12 or I13?

The category depends on which organs are involved; the final character depends on heart failure and the CKD stage. The right-hand column is the “use additional code” note printed at each code in the FY2027 Tabular List:

Category I13- takes precedence whenever both the heart and the kidneys are involved:

“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 codes from I11 or I12.”

The Includes note at I13- reads: any condition in I11.- with any condition in I12.-; cardiorenal disease; cardiovascular renal disease. Two parent codes in this family are not billable: I13.1- has to be carried to I13.10 or I13.11, and N18.3- to N18.30, N18.31 or N18.32.

Which additional codes are required, and in what order?

A hypertensive combination code records that the conditions coexist, not the type of heart failure or the CKD stage, so both additional codes are required:

“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.”

Section I.C.9.a.2 gives the same N18 instruction for I12. The order is fixed by the Tabular notes at the other end of each pair: the code-first note at I50- lists heart failure due to hypertension (I11.0); heart failure due to hypertension with chronic kidney disease (I13.-), and the code-first note at N18- lists hypertensive chronic kidney disease (I12.-, I13.-). The combination code therefore goes first, with the I50 and N18 codes after it (see the code first and use additional code guide).

The use-additional note at N18.6 (code to identify dialysis status (Z99.2)) adds Z99.2 for a patient on dialysis. When the record documents both a CKD stage and ESRD, Section I.C.14.a.1 settles the stage code:

“If both a stage of CKD and ESRD are documented, assign code N18.6 only.”

How do you choose the codes, step by step?

1. Confirm the type of hypertension. Hypertension documented as secondary to another condition goes to I15-, never to I12.
2. Identify heart involvement: heart failure, or a condition in I51.4–I51.7, I51.89 or I51.9.
3. Identify CKD and its documented stage (ESRD means N18.6).
4. Look for a provider statement that either condition is unrelated to the hypertension.
5. Choose the category (heart only I11, kidney only I12, both I13), then the code by heart failure and CKD stage.
6. Add the I50 code for the documented type and acuity, the N18 stage code, and Z99.2 for dialysis.
7. Sequence the combination code before its I50 and N18 codes.

What does this look like on real documentation?

When is hypertension not coded as hypertensive heart or kidney disease?

The presumption stops at a provider statement that the conditions are unrelated:

“CKD should not be coded as hypertensive if the provider indicates the CKD is not related to the hypertension.”

“The same heart conditions (I50.-, I51.4-I51.7, I51.89, I51.9) with hypertension are coded separately if the provider has documented they are unrelated to the hypertension.”

In that case Section I.C.9.a.1 assigns I10 or a code from I15- and sequences by the circumstances of the encounter.

Secondary hypertension is the other exception. The Excludes1 note at I12- lists hypertension due to kidney disease (I15.0, I15.1); renovascular hypertension (I15.0); secondary hypertension (I15.-), so I12 is never reported with an I15 code. Section I.C.9.a.6 requires two codes instead:

“Two codes are required: one to identify the underlying etiology and one from category I15 to identify the hypertension.”

What about acute kidney failure, hypertensive crisis and pregnancy?

Acute kidney failure is reported in addition. The Excludes2 note at I12- lists acute kidney failure (N17-), so both may be coded, and Section I.C.9.a.2 requires it:

“If a patient has hypertensive chronic kidney disease and acute renal failure, the acute renal failure should also be coded. Sequence according to the circumstances of the admission/encounter.”

Hypertensive urgency, emergency or crisis adds a code from I16-, whose code-also note asks for any identified hypertensive disease (I10-I15, I1A). A patient with hypertensive heart and chronic kidney disease in a hypertensive emergency therefore gets I16.1 and the I13 code, sequenced by the reason for the encounter:

“Assign a code from category I16, Hypertensive crisis, for documented hypertensive urgency, hypertensive emergency or unspecified hypertensive crisis.”

In pregnancy, childbirth and the puerperium, pre-existing hypertensive heart and kidney disease is classified to O10- instead; Section I.C.15.d sets the additional code for those cases. With diabetes as well, the code-first note at N18 also lists diabetic chronic kidney disease, such as E11.22; the CKD code page covers that pairing.

What are the most common errors?

• I10 with I50.9, or I10 with an N18 code. Without a statement that the conditions are unrelated, this misses the presumed link. The correct codes are I11.0 with the I50 code, or I12 with the N18 code.
• I11.0 plus I12.9 instead of I13.0. Section I.C.9.a.3 requires I13 when heart disease and CKD are both present.
• I10 beside the combination code. Section I.C.9.a.3 describes the I13 codes as combination codes that include hypertension.
• No N18 code, or N18.9 when a stage is documented. I12 and I13 do not carry the stage.
• A stage that contradicts the combination code. I12.9, I13.0 and I13.10 pair with N18.1–N18.4 or N18.9; I12.0, I13.2 and I13.11 with N18.5 or N18.6.
• I50.9 when the type or acuity is documented. Its inclusion terms (Cardiac, heart or myocardial failure NOS; Congestive heart disease; Congestive heart failure NOS) mark it as the NOS code; see the unspecified codes guide.

What should you check before submitting?

• One combination code from I11, I12 or I13, never two, and no I10 beside it.
• Its final character agrees with the heart failure status and the N18 stage code.
• An I50 code with the documented type and acuity, and an N18 code for the documented stage (N18.6 alone when ESRD is documented).
• Z99.2 with N18.6 when the patient is on dialysis.
• The combination code listed ahead of the I50 and N18 codes.
• Every code valid and billable for FY2027: paste the list into the batch code checker.

Did FY2027 change any of these codes?

No. None of the codes in categories I10, I11-, I12-, I13-, I15-, I16-, I1A-, I50- or N18- was added, expanded, deleted or given a revised description in the FY2027 release. The full list of what did change is on the FY2027 changes page.