Keep in mind these coding tips for chronic kidney disease to improve medical record documentation

The complex nature of chronic kidney disease makes accurate code selection essential. A basic understanding of CKD, its causes and its comorbidities can help you assign the highest specificity of codes.

Chronic kidney disease is a condition characterized by a gradual loss of kidney function. When kidney disease gets worse, the nephrons that filter out wastes and other fluids from the bloodstream lose the ability to filter, causing the kidneys to lose functionality.

Complications of CKD include high blood pressure, anemia, weak bones and nerve damage. CKD may also increase the risk of developing heart or blood vessel disease.

ICD-9-CM codes are based on the severity of CKD. The provider must clearly document the CKD stage to ensure codes are chosen to the highest level of specificity. Coders can’t assign a CKD code based on the glomerular filtration rate alone and should be as specific as possible:

• Stage I — 585.1 (glomerular filtration rate > 90)
• Stage II — 585.2 (mild) (GFR 60-89)
• Stage III — 585.3 (moderate) (GFR 30-59)
• Stage IV — 585.4 (severe) (GFR 15-29)
• Stage V — 585.5 (severe) excludes CKD stage V, requiring chronic dialysis (585.6)
• End stage renal disease (ESRD) — 585.6 or CKD stage V, requiring chronic dialysis
• Unspecified — 585.9

Chronic kidney disease and diabetes
If the patient has CKD caused by diabetes, the code for diabetes would be assigned first according to ICD-9-CM guidelines.

• Assign 250.4X (primary diabetes) or 249.4X (secondary diabetes) followed by the appropriate CKD code.
• Documentation must show causality between the two conditions. For example, diabetic nephropathy or CKD due to diabetes.
• Although the word “with” is considered acceptable linkage within the context of the ICD-9-CM, BCBSM does not consider the word “with” to be an acceptable linking word in provider documentation.

Chronic kidney disease and anemia
When CKD is present, the kidneys may not make enough erythropoietin, a hormone that controls red blood cell production. This may cause anemia to develop. When documentation indicates the link between the two conditions, assign code 285.21, Anemia in CKD. Also report a code from category 585.X, to indicate the stage of CKD.

Chronic kidney disease and hypertension
ICD-9-CM presumes a cause-and-effect relationship, and classifies CKD with hypertension as Hypertensive CKD whether or not it’s documented. So, when CKD is present with hypertension, assign codes from category 403.XX, Hypertensive CKD.

• Assign a fourth digit for hypertensive CKD, 403.XX, based on whether the hypertension is documented as malignant (0), benign (1) or unspecified (9).
• Report a fifth digit to identify the stage of CKD that is documented:
• If CKD stage I through stage IV or unspecified, use 0 for the fifth digit (403.X0)
• If CKD stage V or end-stage renal disease, use 1 for the fifth digit (403.X1).
• Use an additional code to identify the stage of chronic kidney disease (585.1-585.6, 585.9)

Hypertensive heart and chronic kidney disease
Report hypertensive heart and CKD with a code from the combination category 404.XX when both conditions are stated in the diagnosis. The relationship between the hypertension and CKD is still assumed, but heart disease and CKD don’t have an assumed relationship. Documentation must state a cause-and-effect relationship.

• Assign a fourth digit for hypertensive heart and CKD, 404.XX, based on whether the hypertension is documented as malignant (0), benign (1) or unspecified (9).
• Report hypertensive heart and CKD, 404.XX, with a fifth digit according to the relationship documented between the heart failure and CKD and the stage of CKD documented.
• Use “0” for hypertensive heart and CKD without heart failure and CKD stage I through stage IV, or unspecified.
• Use “1” for hypertensive heart and CKD with heart failure and CKD stage I through IV, or unspecified.
• Use “2” for hypertensive heart and CKD without heart failure and CKD stage V or end-stage renal disease.
• Use “3” for hypertensive heart and CKD with heart failure and CKD stage V or ESRD.
• Also use additional codes to identify the stage of chronic kidney disease (585.1-585.6, 585.9) and to code the specific type of heart failure (428.0-428.43), if known.
• More than one code from category 428 may be assigned if the patient has systolic or diastolic failure and congestive heart failure.

Coding kidney dialysis and transplants
Early detection and treatment can often keep chronic kidney disease from getting worse, but when kidney disease progresses it can lead to kidney failure which often requires dialysis or a kidney transplant to maintain life.

• If the patient is admitted solely for dialysis treatment, use V56.0 (renal) dialysis NOS as the primary code and then code V45.11 (renal dialysis status). The renal condition is also assigned as an additional diagnosis.
• Report V45.12 for patients who are noncompliant with renal dialysis. 
• Patients who have undergone a kidney transplant may still have CKD. A kidney transplant does not always restore full kidney function.
• Assign the appropriate CKD (585.X) code for the patient’s stage followed by code V42.0, kidney replaced by transplant.
• Kidney transplant complication codes are only assigned if the complication affects the function of the transplanted organ.
• Two codes are required to fully describe a transplant or rejection of transplant complication, code 996.81 and a secondary code that identifies the complication.

To see a compilation of additional coding tips that have been featured in The Record over the past 14 months, click here. Also, be sure to check out next month’s issue of The Record, which will include an article on coding tips for pregnancy complications.

None of the information included in this document should be considered legal advice. As such, it is the provider’s responsibility to ensure that all coding and documentation are done in accordance with applicable state and federal laws and regulations.