ICD-10 Code for Hypertension With Chronic Kidney Disease: I12.9, I12.0 and I13 by Stage

When a patient has both high blood pressure and chronic kidney disease, ICD-10-CM does not let you code them as two unrelated problems. The classification assumes the hypertension and the kidney disease are linked, and it has combination codes for exactly that: I12 for hypertensive chronic kidney disease, and I13 when the heart is involved too. Each one needs an N18 code to show the stage.

This page gives the exact code pair for every CKD stage, end-stage renal disease and dialysis, heart failure, diabetes, and pregnancy, with worked examples. All codes and rules are from the FY2027 code set and Official Guidelines, in effect from October 1, 2026 to September 30, 2027. For plain hypertension (I10) and the rest of the I10 to I16 family, see the main guide to the ICD-10 code for hypertension.

Quick Answer

Hypertension with chronic kidney disease is coded with I12 plus an N18 code for the stage. Use I12.9 with N18.1, N18.2, N18.30, N18.31, N18.32, N18.4 or N18.9 for stage 1 through 4 or unspecified CKD, and I12.0 with N18.5 or N18.6 for stage 5 or end-stage renal disease. If the patient also has hypertensive heart disease or heart failure, use a code from I13 instead (I13.0, I13.10, I13.11 or I13.2), plus the N18 stage and an I50 code for any heart failure. The link between hypertension and CKD is presumed, so code the combination even if the provider does not write “due to”, unless the provider says the CKD is not caused by the hypertension.

In this guide:

• The Two Codes You Always Need
• ICD-10 Code for Hypertension With CKD, Stage by Stage
• Stage 5, End-Stage Renal Disease, Dialysis and Transplant
• Hypertensive Heart and Chronic Kidney Disease (I13)
• Hypertension, Diabetes and CKD Together
• Benign, Malignant or Uncontrolled Hypertension With CKD
• When Not to Use I12
• Hypertensive CKD in Pregnancy
• Common Coding Mistakes
• The Verdict

The Two Codes You Always Need

Category I12, Hypertensive chronic kidney disease, is assigned whenever hypertension and a condition in N18 (chronic kidney disease) are both present. The Official Guidelines explain why: the Alphabetic Index links the two conditions with the word “with”, and the classification presumes a causal relationship between conditions linked that way. You code them as related even when the provider has not written that one caused the other. The only exception is documentation that clearly says the CKD is not related to the hypertension.

I12 never stands alone. It has two codes, and each carries a “use additional code” note telling you to add the N18 stage:

Sequencing: the I12 code comes first and the N18 code second. N18 carries a “code first” note for hypertensive chronic kidney disease (I12.-, I13.-), and the guidelines say the N18 code is used as a secondary code to identify the stage. I12.9 is also the code for “hypertensive renal disease” or “hypertensive nephropathy” with no other detail.

ICD-10 Code for Hypertension With CKD, Stage by Stage

Every stage pairs the same way: I12.9 up to stage 4, I12.0 from stage 5. The guidelines define stage 2 as mild, stage 3 as moderate and stage 4 as severe CKD.

Worked examples:

• “Hypertensive CKD stage 3b”: I12.9, N18.32.
• “HTN, CKD 4”: I12.9, N18.4. The provider does not need to write “hypertensive” for the combination to apply.
• “Moderate CKD with hypertension”, no stage number: stage 3 is moderate, but without 3a or 3b it is I12.9, N18.30.
• “Hypertension and CKD stage 5, not yet on dialysis”: I12.0, N18.5.
• “Hypertensive nephrosclerosis” or “hypertensive nephropathy” with CKD stage 2: I12.9, N18.2; these terms are included in I12.

Stage 5, End-Stage Renal Disease, Dialysis and Transplant

• Stage 5 versus ESRD. N18.5 is stage 5; N18.6 is end-stage renal disease, which includes CKD requiring chronic dialysis. Both go with I12.0. If the record documents both a CKD stage and ESRD, the guidelines say to assign N18.6 only.
• Dialysis. N18.6 has a “use additional code” note for dialysis status. A patient with hypertensive ESRD on dialysis is I12.0, N18.6, Z99.2 (Dependence on renal dialysis).
• Kidney transplant. A transplant may not fully restore kidney function, so CKD after a transplant is not by itself a transplant complication. Code the N18 stage and Z94.0 (Kidney transplant status). With hypertension that is, for example, I12.9, N18.31, Z94.0. Only code a transplant complication (failure, rejection) when it is documented; if the record is unclear, query the provider.

Hypertensive Heart and Chronic Kidney Disease (I13)

When hypertension, heart disease and CKD are all present, I13 replaces both I11 (hypertensive heart disease) and I12. The guidelines are explicit: use a code from I13, not codes from I11 or I12. The heart disease is presumed hypertensive in the same way as the kidney disease, for conditions such as heart failure (I50.-) and the other heart conditions listed in the hypertension guideline.

Worked examples:

• “Hypertensive heart and kidney disease with chronic diastolic heart failure, CKD stage 3a”: I13.0, I50.32, N18.31.
• “Hypertension, heart failure (type not specified), CKD stage 4”: I13.0, I50.9, N18.4.
• “Hypertensive heart and chronic kidney disease, no heart failure, ESRD on dialysis”: I13.11, N18.6, Z99.2.
• “Cardiorenal disease” with hypertension and no heart failure, stage unknown: I13.10, N18.9. Cardiorenal and cardiovascular renal disease are included in I13.

Hypertension, Diabetes and CKD Together

Diabetes and hypertension are the two most common partners of CKD, and the classification links each of them to CKD separately. Diabetes and CKD are linked by “with” in the same way, through E11.22, Type 2 diabetes mellitus with diabetic chronic kidney disease (E10.22 for type 1). When all three are present, code both links and the stage:

The N18 code goes after both: its “code first” note lists diabetic CKD (E08.22, E09.22, E10.22, E11.22, E13.22) and hypertensive CKD (I12.-, I13.-). That note fixes only where N18 goes; there is no instruction placing E11.22 ahead of I12 or the reverse, so the first-listed of the two follows the general rules for the reason for the encounter. Note that diabetes and hypertension without CKD have no presumed link and no combination code; that case is covered in the main hypertension guide.

Benign, Malignant or Uncontrolled Hypertension With CKD

In ICD-10-CM, “benign”, “malignant”, “accelerated”, “essential” and “systemic” are nonessential modifiers of hypertension in the Alphabetic Index, and I10 lists benign and malignant hypertension among its inclusion terms. None of them changes the code. So “benign hypertension with CKD stage 3” and “malignant hypertension with stage 4 CKD” are coded exactly like any hypertension with CKD: I12.9, N18.30 and I12.9, N18.4.

“Controlled” and “uncontrolled” hypertension also stay in the I10 to I15 categories, so they make no difference to the CKD combination either. A documented hypertensive urgency or emergency is different: add a code from I16 (hypertensive crisis) as well, with sequencing based on the reason for the encounter.

When Not to Use I12

• The provider says the CKD is not due to the hypertension. Then CKD should not be coded as hypertensive: code the hypertension (I10) and the N18 stage separately, plus the documented cause of the kidney disease.
• Secondary hypertension. If the hypertension is caused by the kidney disease (secondary or renovascular hypertension), it belongs in I15 (I15.0 renovascular, I15.1 secondary to other renal disorders), which I12 excludes. I15 needs the underlying condition coded as well.
• Acute kidney injury only. Acute kidney failure (N17.-) is not CKD and does not trigger I12. When a patient with hypertensive CKD also has acute renal failure, code both, sequenced by the circumstances of the encounter.
• Elevated blood pressure without a hypertension diagnosis. That is R03.0, and with CKD it does not create an I12 combination.

Hypertensive CKD in Pregnancy

Pre-existing hypertensive CKD in a pregnant patient is coded in chapter 15, which takes sequencing priority, with O10.2- (Pre-existing hypertensive chronic kidney disease complicating pregnancy, childbirth and the puerperium): O10.211, O10.212, O10.213 or O10.219 by trimester, O10.22 for childbirth and O10.23 for the puerperium. O10.2 tells you to use an additional code from I12 to identify the type, and that I12 code then takes its N18 stage. With heart involvement, use O10.3- with an I13 code. Example: hypertensive CKD stage 3a in the second trimester is O10.212, I12.9, N18.31.

Common Coding Mistakes

• Coding I10 with N18. Hypertension plus CKD is I12 (or I13), not I10, unless the provider documents that they are unrelated.
• Leaving out the N18 code. I12 and I13 do not carry the stage on their own; the N18 code is required.
• Mismatching the pair. I12.9 goes only with stages 1 to 4 or unspecified; I12.0 only with stage 5 or ESRD.
• Using I11 and I12 together. Heart and kidney disease with hypertension is one I13 code.
• Coding both N18.5 and N18.6. If a stage and ESRD are both documented, use N18.6 only.
• Forgetting Z99.2 or Z94.0. Dialysis dependence and kidney transplant status are separate codes.
• Using N18.30 when 3a or 3b is documented. Use the specific subtype.

The Verdict

Hypertension with chronic kidney disease is always a combination: I12.9 with the N18 code for stage 1 to 4 or unspecified CKD, or I12.0 with N18.5 or N18.6 for stage 5 or ESRD. Add the heart and it becomes I13 (with an I50 code for heart failure); add diabetes and E11.22 or E10.22 joins the pair; add dialysis and Z99.2 follows N18.6. The link is presumed, so the only time hypertension and CKD are coded separately is when the provider says they are unrelated.

For I10 itself, hypertensive heart disease, secondary hypertension, hypertensive crisis and R03.0, see the full ICD-10 hypertension code guide.