When you are diagnosing a diabetic patient, the first rule of thumb is to use the diagnosis code that best explains why you have seen the patient but that's not always as easy as it sounds.
The diagnosis code will represent either diabetes without mention of complication, 250.0x, or diabetes with ophthalmic manifestations, 250.5x. The fifth digit of the diagnosis code identifies whether the patient has type I or type II diabetes and whether it is "controlled" or "uncontrolled," nonspecific terms that indicate whether the patient's blood sugar level is kept within acceptable levels by his or her treatment regimen. "[T]he fifth digit is very important it tells the carrier whether the patient has any ill effects visually from the diabetes," says Melissa K. Duchak, CPC, an
ophthalmology coding consultant based in Sinking Spring, Pa. If there is an ophthalmic manifestation of diabetes, ICD-9-CM instructs you to designate a second diagnosis code because chronic manifestations require a code from the 250.5x category in addition to a code that specifically identifies the manifestation.
Applying this second diagnosis is even required if the index does not indicate a need for dual coding. "When a patient comes in for an annual diabetic exam, you must document this as the reason they are in, but you can also document any symptoms they may have at the time, such as blurred vision, dry eye, etc.," says Sherry Searson, CPC, an independent coding consultant based in Charleston, S.C. "This should get Medicare and most private insurers to pay for the exam based on medical necessity." A caution to coders: Payers do not require the second diagnosis code of diabetes, and if it is added and is not to the highest level of specificity, it can cause a claim denial. Here are some examples of coding ophthalmic manifestations of diabetes generated from the Northeast Health Care Quality Foundation Payment Error Prevention Program:
Example 1: A 70-year-old insulin-dependent patient is referred to an ophthalmologist for a suspected condition related to her diabetes mellitus. The ophthalmologist determines she has proliferative diabetic retinopathy. The coding scenario would be primary diagnosis code 250.51, Type I insulin-dependent diabetes with ophthalmic manifestations, and secondary diagnosis code 362.02, Proliferative diabetic retinopathy. If it had been nonproliferative background diabetic retinopathy, the secondary diagnosis code would have had to have been adjusted. Example 2: A 30-year-old non-insulin-dependent diabetic presents with developing loss of vision. The ophthalmologist discovers he has an early onset of quickly developing senile cataracts, which could not be considered a diabetic complication.
The coding scenario would be a primary diagnosis code of 250.02, Type II non-insulin-dependent diabetes without mention of complication, with a secondary diagnosis code of 366.10, Senile cataract, [...]
