ICD 10 Coding Alert

Urology:

Turn to N20, N21 for Most Calculus Diagnoses

It’s just like real estate: Location is everything.

As a urology coder, you see calculus diagnoses on a regular basis. ICD-10 has expanded your choices, but for stone diagnoses you will find most of your most common ones in two code families: N20- (Calculus of kidney and ureter …) and N21- (Calculus of lower urinary tract …). Coding notes specify that N21 includes calculus of the lower urinary tract with cystitis and urethritis.

Previous diagnoses:  In the past when you coded by ICD-9, you had a single choice for ureter and two choices for bladder: 592.1 (Calculus of ureter), and 594.0 (Calculus in diverticulum of bladder), and 594.1 (Other calculus in bladder).

Updated options: The N20 family expands to the following codes representing kidney and ureter calculi:

  • N20.0 – Calculus of kidney
  • N20.1 – Calculus of ureter
  • N20.2 – Calculus of kidney with calculus of ureter
  • N20.9 – Urinary calculus, unspecified

Diagnoses for calculus of the lower urinary tract follow the same structure:

  • N21.0 – Calculus in bladder 
  • N21.1 – Calculus in urethra
  • N21.8 – Other lower urinary tract calculus 
  • N21.9 – Calculus of lower urinary tract, unspecified

Remember that, if possible, do not use unspecified ICD-10 diagnostic codes. Medicare and many carriers will not reimburse for any services billed with “unspecified” ICD-10 diagnoses.

The good news: “ICD-10 coding is very specific,” says Catherine Brink, BS, CMM, CPC, CMSCS, CPOM, president of Healthcare Resource Management Inc. Spring Lake, New Jersey. That means with all the additional choices in ICD-10, you should be resorting to “unspecified” options less often than when you still followed ICD-9.