Internal Medicine Coding Alert

 Narrow down 250 code choices with these 5 hints.

Even experienced coders can become baffled when documenting diabetes diagnoses. And with so many variables, including type, control, drug use, complications, and comorbidities, it's easy to understand why.

So, to help you simplify your choices and find the most specific code possible, here are five steps you can take to streamline the way you code this metabolic disorder.

Code for Diabetes Type

Coders in primary care can quickly narrow down their diabetes code choices by bypassing three of the five diabetes categories that are rarely used in the primary care setting.

As the American Academy of Family Physicians (AAFP) explains, category E08 (Diabetes mellitus due to underlying condition) features secondary codes that are caused by underlying conditions such as cystic fibrosis or diseases of the pancreas, while category E09 (Drug or chemical induced diabetes mellitus), as the descriptor explains, are secondary codes used when the diabetes is brought on by drug or toxin poisoning (Source: https://www.aafp.org/fpm/2013/1100/fpm20131100p22-rt1.pdf).

Primary care coders will also rarely reach for category E13 (Other specified diabetes mellitus), as the codes in this subsection are used when genetic defects and pancreatectomy cause the diabetes.

This leaves internal medicine coders with two main categories for the two main types of diabetes: E10 (Type 1 diabetes mellitus) and E11 (Type 2 diabetes mellitus).

Coding caution: Marcella Bucknam, CPC, CCS-P, COC, CCS, CPC-P, CPC-I, CCC, COBGC, manager of clinical compliance with PeaceHealth in Vancouver, Washington, reminds coders and providers not to fall back on coding E11 as the default for the condition. "If your patients have type 1 diabetes, their care will be much more complex, and this will not be supported if the diagnosis doesn't match the treatment. If your diagnosis doesn't match the treatments provided," Bucknam adds, "the treatments may not be paid."

Code for Control

Both AAFP and Joy Dugan and Jay Shubrook, authors of "International Classification of Diseases-10 Coding for Diabetes" (http://clinical.diabetesjournals.org/content/diaclin/early/2017/08/10/cd16-0052.full.pdf), then suggest coders look at the level or degree of diabetes control.

ICD-10 does not include any explicit reference to controlled or uncontrolled diabetes. However, the level of control is indicated as a complication in the fourth and fifth characters: EXX.64X in the case of hypoglycemia (blood sugar levels below 70 mg/dl), and EXX.65 for hyperglycemia (blood sugar levels above 130 mg/dl).

Another fourth character, 9, indicates that the condition is controlled (e.g. E10.9 (Type 1 diabetes mellitus without complications)). But using 9 "should be the exception rather than the rule," according to Dugan and Shubrook, "given that most people with diabetes have either suboptimal control, complications, or both."

Code for Drug Use

In order to manage their diabetes, many patients turn to insulin use. As this is not indicated in the E11 codes, Chelle Johnson, CPMA, CPC, CPCO, CPPM, CEMC, AAPC Fellow, billing/credentialing/auditing/coding coordinator at County of Stanislaus Health Services Agency in Modesto, California, suggests coders keep Z79.4 (Long term (current) use of insulin) or Z79.84 (Long term (current) use of oral hypoglycemic drugs) at their fingertips when coding diabetic patients. (There is no corresponding instruction for the E10 codes, as type 1 diabetes is understood to be insulin-dependent.)

AAFP and Dugan and Shubrook also remind coders that "long-term" simply means that the drug therapy is intended for an extended duration, and the code can be used immediately once the drug use begins.

Code for Complications

This is the tricky part, because the complications are numerous. So, Johnson reminds coders "to be on the lookout for co-diseases such as thyroid disease, hearing loss, cancer, neuropathy, feet ulceration, hypertension, etc." Many can be coded with the following fourth-digit E10 and E11 subdivisions:

• EXX.1- - ... with ketoacidosis
• EXX.2- - ... with kidney complications
• EXX.3- - ... with ophthalmic complications
• EXX.4- - ... with neurological complications
• EX X.5- - ... with circulatory complications
• EXX.6- - ... with other specified complications (includes musculoskeletal, oral, and skin compli­cations; hypoglycemia; and hyperglycemia)
• EXX.8- - ... with unspecified complications.

The only exception to this sequence is E11.0- (Type 2 diabetes mellitus with hyperosmolarity), as this complication, where extremely high blood sugar levels occur without the presence of ketones, is unique to type 2 diabetes.

Code for Comorbidities

Diabetes is also often linked to many other diseases, so it is important to code them as well. Among the most common are:

• E66.- - Overweight and obesity
• E78.- - Disorders of lipoprotein metabolism and other lipidemias 
• I10 - Essential (primary) hypertension
• L97.- - Non-pressure chronic ulcer of lower limb, not elsewhere classified.

Johnson notes that obesity and type 2 diabetes go hand in hand. "We need to code for this condition as well as BMI (body mass index) if noted," she says, adding that coders should "code as many codes as necessary to describe all complications and associated conditions and sequence them based on the reason for the encounter."

As a final note, Bucknam reminds coders why they should code so specifically: "More and more payers are requiring specific diagnoses to support the need for treatments and supplies," she says, adding that "providers also need to improve the specificity of their diagnosis documentation as physician payment becomes increasingly value-based and payments are risk-adjusted based on patient conditions."

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