Oncology & Hematology Coding Alert

Question: ICD-10-CM seems to have different codes for type I and type II diabetes. Are the two no longer grouped together as in ICD-9-CM? Please explain the difference for ICD-10-CM and ICD-9-CM.

Washington Subscriber

Answer: Effective Oct. 1, you have different diagnosis codes for type I and type II diabetes. The ICD-10-CM coding options are distinct and specific when compared to the ICD-9-CM options.

Type I: Code all type I patients by starting out with the E10 series (Type I diabetes mellitus), and then you’ll move on from there after reviewing the patient’s chart to determine whether any further complications or manifestations exist.

Type II: Code all type II patients by starting out with the E11 series (Type 2 diabetes mellitus).

Don’t assume all pediatric patients have type I diabetes, just because type I diabetes has the phrase “juvenile onset” in parentheses following the descriptor. Physicians are treating type II diabetes developed in childhood or adolescence more often than they were a few years ago.

Default: If there is no documentation that actually states type I or type II, the diagnosis code will default to type II diabetes — category E11. You should never assume a patient has Type I just because he/she is a “juvenile,” and likewise you cannot assume an older patient has Type II.

Reference: Official Coding Guidelines I.C.4.a.1 and I.C.4.a.2.

How was ICD-9-CM different? This is strikingly different from what you have been reporting in ICD-9-CM.

Under ICD-9-CM, for a patient who presents with diabetes, you used to determine the fourth digit for 250.xx (Diabetes mellitus) according to the type of diabetic complication the patient has, if any. If the patient presented with diabetes without any complications, your first four digits used to be 250.0 (Diabetes mellitus without mention of complication).

Under ICD-9-CM, the fifth digit provides the final two pieces of information on the patient’s diabetic condition: the diabetes type (I or II) and whether it is controlled.