ICD-10 doesn't have to be intimidating

The idea of a new code set should be familiar by now to internists. To help internists become even more comfortable with ICD-10, this column will answer questions that ACP has received from members by offering examples of the codes for common diagnoses.

Q: What are the differences in the structures of ICD-9 versus ICD-10 codes? Are the code numbers random, or do they follow some type of order?

A: ICD-10 uses 3 to 7 alphabetic and numeric characters and full code titles, but the format is very similar to that of ICD-9.

ICD-10 uses codes that are longer (in some cases) than those of ICD-9, following a basic structure:

• characters 1-3 will now refer to the code category;
• character 1 is always alphabetic;
• characters 2-3 are always numeric;
• characters 4-6 will cover clinical details such as severity, etiology, and anatomic site (among others) and are alphabetic or numeric and
• character 7 will serve as an extension when necessary and will be either alphabetic or numeric.

For illustration, here are a few brief crosswalks from ICD-9 to ICD-10 coding.

In ICD-9, headache is coded as 784.0; in ICD-10, it is coded as R51. ICD-9 uses 724.5 for backache, unspecified, while ICD-10 uses the following more specific codes: M54.9, dorsalgia, unspecified; M54.89, other dorsalgia; M54.6, pain in thoracic spine; M54.5, low back pain; and M53.3, sacrococcygeal disorders, not elsewhere classified. For atrial fibrillation, ICD-9 uses the code 427.31, while ICD-10 uses the following more specific codes: I48.0, paroxysmal atrial fibrillation; I48.1, persistent atrial fibrillation; I48.2, chronic atrial fibrillation; and I48.91, unspecified atrial fibrillation.

Q: I've heard that ICD-10 combines codes, but I don't understand what that means. Can you explain it?

A: A distinguishing feature of ICD-10 is that it includes “combination codes.” These allow a physician to describe multiple diagnoses by using only 1 code or to describe a diagnosis with its complication. This device reduces the number of codes needed while still providing detailed information.

For example, in ICD-9 the codes for type 2 diabetes with retinopathy are 250.5, diabetes with ophthalmic manifestations, and 362.01-362.07, retinopathy.

In comparison, the ICD-10 codes describing type 2 diabetes with retinopathy (with or without macular edema) are as follows:

• E11.31: Type 2 diabetes mellitus with unspecified diabetic retinopathy
• E11.319: Type 2 diabetes with unspecified diabetic retinopathy without macular edema
• E11.32: Type 2 diabetes with mild nonproliferative diabetic retinopathy
• E11.329: Type 2 diabetes with mild nonproliferative diabetic retinopathy without macular edema
• E11.33: Type 2 diabetes with moderate nonproliferative diabetic retinopathy
• E11.339: Type 2 diabetes with moderate nonproliferative diabetic retinopathy without macular edema
• E11.34: Type 2 diabetes with severe nonproliferative diabetic retinopathy
• E11.349: Type 2 diabetes with severe nonproliferative diabetic retinopathy without macular edema
• E11.35: Type 2 diabetes with proliferative diabetic retinopathy
• E11.359: Type 2 diabetes with proliferative diabetic retinopathy without macular edema

The implementation deadline for ICD-10 remains Oct. 1, 2014. There is no indication that there will be another delay; in response, ACP's position is to provide its members with information and resources to help them prepare for the coding transition. ACP's ICD-10 resources are online.

It's important to continue to make progress toward implementation of ICD-10. It's only 1 year away. To assess whether your practice is on track for implementation, please check your progress against the ACP Physician and Practice Timeline, online.

Q: What services do internists bill most frequently? Is it only the evaluation and management codes?

A: Actually, it's more than the E/M codes. ACP doesn't have access to all insurance claims data, but we do have the publicly available Medicare claims data. This Table lists the top CPT codes for internists in order of frequency, ranging from approximately 21 million to approximately 2 million claims annually. Four of the most popular codes are for laboratory services billed by internists but processed under the Clinical Laboratory Fee Schedule, not the Physician Fee Schedule.