Urology Coding Alert

Chronic kidney disease (CKD) is defined by the Center for Disease Control and Prevention (CDC) as “a condition in which the kidneys are damaged and cannot filter blood as well as they should. Because of this, excess fluid and waste from blood remain in the body and may cause other health problems” (www.cdc.gov/kidneydisease/basics.html).

Conditions such as diabetes and hypertension can cause CKD. But CKD can, in turn, cause numerous conditions that require management and treatment. Because CKD causes chronic inflammation, and because inflammation weakens a patient’s immune system, patients with CKD are at risk for developing urinary tract infections (UTIs). Patients with CKD are also at risk for developing kidney stones.

So, if your urologist is treating patients for these common conditions caused by CKD, here’s what you need to know.

Code for UTI

If your provider diagnoses the patient with a UTI, coding to “N39.0 [Urinary tract infection, site not specified] may be attractive and the obvious choice to the provider. However, there are a couple of issues with this,” says Donna Walaszek, CCS-P, billing manager, credentialing/ coding specialist for Northampton Area Pediatrics LLP in Northampton, Massachusetts.

First, you will need to provide a more specific code that pinpoints the site of the infection, if known. For example, if the location of the condition is the kidney (or pyelonephritis), you would look to N10 (Acute pyelonephritis). If the infection is in the bladder (cystitis), you would choose from the N30.- (Cystitis) codes. For any infection stemming from the urethra (urethritis), you would choose N34.- (Urethritis and urethral syndrome).

Then, you will need to pay attention to your provider’s notes to zero in on the exact code.

For the N30.- codes, check for acute or chronic cystitis diagnosis. If it’s acute, use N30.0- (Acute cystitis). For chronic, you’ll use N30.1- (Interstitial cystitis) or N30.2- (Other chronic cystitis). Also check to see if the provider has documented that the patient’s urine has blood in it and use R31.- (hematuria).

For the N10, N30.- and N34.- codes, remember to use an additional code from B95-B97 (Bacterial and viral infectious agents) to identify the cause for the infection, if applicable, after your provider has administered a test. So, you should keep these additional common bacterium or virus codes handy:

• B96.2- (Escherichia coli [E. coli] as the cause of diseases classified elsewhere)
• B96.1 (Klebsiella pneumoniae [K. pneumoniae] as the cause of diseases classified elsewhere)
• B96.4 (Proteus (mirabilis) (morganii) as the cause of diseases classified elsewhere)
• B95.2 (Enterococcus as the cause of diseases classified elsewhere)
• B95.7 (Other staphylococcus as the cause of diseases classified elsewhere)

Code for Kidney Stones

Like the UTI codes, the ICD-10-CM codes related to kidney stones are based on whether the stone is located in the kidney, ureter, or bladder. The relevant codes appear below:

• N20.0 (Calculus of kidney)
• N20.1 (Calculus of ureter)
• N20.2 (Calculus of kidney with calculus of ureter)
• N20.9 (Urinary calculus, unspecified)
• N21.0 (Calculus in bladder)
• N21.8 (Other lower urinary tract calculus)
• N21.9 (Calculus of lower urinary tract, unspecified)

Remember: Kidney stones can also form in a patient’s urethra, which you’ll code to N21.1 (Calculus in urethra) if documented by your provider.

Code for CKD

After you have coded the patient’s primary diagnosis, and assuming the provider has listed CKD as its cause, you can then go on and code for the patient’s CKD. To code the condition correctly, you must first consult ICD-10-CM guideline I.C.14.a.1. This guideline explains that there are different levels of CKD severity. The five stages are:

• Stage 1, code N18.1 (Chronic kidney disease, stage 1), identifies longstanding and persistent renal disease
• Stage 2, code N18.2, (…stage 2 (mild) equates to mild CKD
• Stage 3, codes N18.30 (… stage 3 unspecified), N18.31 (…stage 3a), and N18.32 (… stage 3b) cover moderate CKD conditions
• Stage 4, code N18.4 (…stage 4 (severe)) denotes severe CKD
• Stage 5, code N18.6 (End stage renal disease) denotes when the provider has documented ESRD

But before you finally assign a CKD code, make sure you also pay attention to these three important hints:

Hint 1: If both a stage of CKD and ESRD are documented, ICD-10-CM instructs you to assign code N18.6 only.

Hint 2: Avoid using clinical guidelines to distinguish between N18.31 and N18.32. The National Kidney Foundation defines CKD stage 3a as a glomerular filtration rates (eGFR) of between 45 and 59 mL/minute, while it defines stage 3b as a GFR of between 30 and 44 mL/minute (https://www.kidney. org/atoz/content/gfr). However, as a coder, you cannot assign either code, or any other CKD stage code for that matter, based on a patient’s eGFRs. Code assignment can only come from a provider’s documentation.

Hint 3: Last, the guidelines also go on to provide instruction on codes and sequencing of codes for particular conditions that cause CKD. They tell you to code first any associated diabetic chronic kidney disease using one of the following codes:

• E08.22 (Diabetes mellitus due to underlying condition with diabetic chronic kidney disease)
• E09.22 (Drug or chemical induced diabetes mellitus with diabetic chronic kidney disease)
• E10.22 (Type 1 diabetes mellitus with diabetic chronic kidney disease)
• E11.22 (Type 2 diabetes mellitus with diabetic chronic kidney disease)
• E13.22 (Other specified diabetes mellitus with diabetic chronic kidney disease)

You will also need to code for any hypertensive chronic kidney disease using one of the following, when applicable:

• I12.- (Hypertensive chronic kidney disease)
• I13.- (Hypertensive heart and chronic kidney disease)

So, you should use one or more of these codes, if appropriate, to paint the whole picture of the patient’s condition.