Internal Medicine Coding Alert

Don't let coding for multiple conditions trip you up

Each time you choose a fourth digit for diabetes diagnosis code 250.xx you also need to select the appropriate code to identify the specific diabetic manifestation.

Although the ICD-9 manual lists several possible manifestation code choices below each fourth-digit descriptor you should realize that this is "definitely not an exhaustive list " says Alison Nicklas RHIT CCS director of education and training for Precyse Solutions based in King of Prussia Pa.

For example the ICD-9 manual lists 583.81 (Nephropathy) and 581.81 (Nephrosis) as possible manifestation codes below 250.4x (Diabetes with renal manifestations). But the manual doesn't list 585 (Chronic renal failure) even though this code is a possible renal manifestation. 

Avoid coding pitfalls with these tips for five diabetes complications:

1. Ketoacidosis: Diabetes' most serious acute metabolic complication is diabetic ketoacidosis (DKA) says Shelley Wojtasczyk MS FNP-C a nurse practitioner in a family medicine clinic in Arcade N.Y. The acidosis complication also occurs in patients with chronic and acute alcoholism she says. When coding for diabetic complications be sure the medical chart states whether the patient has diabetic ketoacidosis.

Only one code: Don't worry about finding an additional code to identify the ketoacidosis as you would with other diabetic complications Nicklas says. Code 250.1x specifies that the patient has diabetic ketoacidosis and "that one code tells the whole story " she says.

2. Renal failure: Diabetic patients can have nephropathy which leads to kidney failure Wojtasczyk says.

If the physician's documentation indicates that the patient has chronic renal failure caused by diabetic nephrotic syndrome all you really need to code is 250.4x and 585 (Chronic renal failure) says Nicklas who presented in a March 11 audio seminar titled  "Diagnosis Coding for Diabetes" for the American Health Information Management Association (AHIMA).

However if you prefer to code all three conditions you can also list 581.81 (Nephrosis) she adds.

3. Hypertension and renal failure: A diabetic patient may present with hypertension and renal failure as a result. If this is well documented you only need two codes Nicklas says. Assign one code for the diabetes with renal manifestations (250.4x) and one code for the hypertension with renal failure (403.91).

You don't have to list any other code because the hypertension code includes renal failure she says. You can assign 583.81 (Nephritis and nephropathy) in addition but remember that this is optional.

4. Cataracts: Internal medicine coders must understand that not all diabetic patients have diabetic cataracts (commonly called snowflake cataracts) Nicklas says. "Studies have shown that most diabetics actually have the more common senile cataracts " she says.

Snowflake cataracts are rare. Most physicians find them in diabetic patients Wojtasczyk adds.

To report diabetic cataracts the physician must document the diabetes as the cause. For diabetic cataracts use 250.5x (Diabetes with ophthalmic manifestations) and 366.41 (Diabetic cataract).

However for a diabetic patient with mature senile cataracts use 250.0x (Diabetes mellitus without mention of complication) and 366.17 (Senile cataract; total or mature cataract). 

5. Gestational diabetes: Gestational diabetes affects women during late pregnancy Wojtasczyk says. To report this condition use 648.8x (Other current conditions in the mother classifiable elsewhere but complicating pregnancy childbirth or the puerperium; abnormal glucose tolerance). No code from the 250 series is necessary. 

Important: Do not use 648.8x for a patient the internist or another physician diagnosed with diabetes prior to the pregnancy.

For a woman who has an established diabetes diagnosis that is complicating her pregnancy you should report 648.0x (Other current conditions in the mother classifiable elsewhere but complicating pregnancy childbirth or the puerperium; diabetes mellitus) and then 250.xx.

You should assign the fourth digit to the 250 code based on whether the physician documented any complications.