September 10, 2019
Area(s) of Interest: Payor Issues and Reimbursement Practice Management 

CPR’s “Coding Corner” focuses on coding, compliance, and documentation issues relating specifically to physician billing. This month’s tip comes from Deborah Marsh, senior content specialist for AAPC, a training and credentialing association for the business side of health care.

The updated ICD-10 2020 code set will be effective Oct. 1, 2019. You can prepare now by viewing the updated codes and official guidelines, paying particular attention to the diagnosis codes and encounter codes you report most often.

Below is a selection from the more than 300 changes that are coming soon. Early training is worth the effort because payors check ICD-10 codes to evaluate medical necessity for the services you report. That means these diagnosis codes will help support proper reimbursement for your claims.

Circulatory system coding will get more specific

ICD-10 2020 includes several changes for Chapter 9: Diseases of the circulatory system (I00-I99).

First, there is an instruction change under I21.A1 Myocardial infarction type 2. In place of 2019’s “Code also” note, you will find an instruction to “Code first” the underlying cause, such as anemia, chronic obstructive pulmonary disease, paroxysmal tachycardia or shock. This change is important because it relates to proper sequencing of the codes on your claim.

The 2020 ICD-10-CM Official Guidelines for Coding and Reporting reflect this note change, as well, in Section I.C.9.e.5. The updated guideline states, “Type 2 myocardial infarction (myocardial infarction due to demand ischemia or secondary to ischemic imbalance) is assigned to code I21.A1, Myocardial infarction type 2 with the underlying cause coded first.” (The guidelines mark updates in bold to make them easier to find.)

Next, your atrial fibrillation code options will increase. Four-character code I48.1 Persistent atrial fibrillation will divide into these new codes that will require five characters:

• I48.11 Longstanding persistent atrial fibrillation
• I48.19 Other persistent atrial fibrillation.

Code I48.2 Chronic atrial fibrillation also will divide into two new five-character code options:

• I48.20 Chronic atrial fibrillation, unspecified
• I48.21 Permanent atrial fibrillation.

Two more groups of changes apply to I80.0- Phlebitis and thrombophlebitis and I82.- Other venous embolism and thrombosis. In each case, ICD-10 2020 adds codes specific to right, left, bilateral, and unspecified peroneal vein and calf muscular vein. For embolism and thrombosis, you’ll have one set of options for acute and another for chronic, such as I82.451 Acute embolism and thrombosis of right peroneal vein and I82.551 Chronic embolism and thrombosis of right peroneal vein.

Pressure-induced deep tissue damage will add to pressure ulcer code options

The 2019 ICD-10 code set includes numerous codes for pressure ulcers because each code includes details such as site, side and stage (for example, L89.011 Pressure ulcer of right elbow, stage 1). The 2020 code set makes the list of codes even longer by adding ICD-10 codes for pressure-induced deep tissue damage. Like other pressure ulcers, you’ll code based on site and side, such as L89.016 Pressure-induced deep tissue damage of right elbow.

The 2020 ICD-10 official guidelines again get updates in line with the 2020 code changes. Section I.C.12.a.1 adds “deep tissue pressure injury” in this sentence: “The ICD-10-CM classifies pressure ulcer stages based on severity, which is designated by stages 1-4, deep tissue pressure injury, unspecified stage, and unstageable.”

The 2020 guidelines also include a new subsection at I.C.12.a.7:

7. Pressure-induced deep tissue damage

For pressure-induced deep tissue damage or deep tissue pressure injury, assign only the appropriate code for pressure-induced deep tissue damage (L89.--6).

Orbital fracture coding will have new codes

Expect ICD-10 2020 to include several new diagnosis codes for orbital fractures that allow you to report with more precision.

Each of the new subcategories below has separate codes for right, left and unspecified side:

• S02.12- Fracture of orbital roof
• S02.83- Fracture of medial orbital wall
• S02.84- Fracture of lateral orbital wall.

For example, this code is specific to the left side (note the extension to the seventh character): S02.842A Fracture of lateral orbital wall, left side, initial encounter for closed fracture.

New subcategory S02.85- (Fracture of orbit, unspecified) does not include right/left options and is appropriate for fracture of orbit or orbit wall when the documentation doesn’t direct you to a more specific code.

Personal history of in-situ neoplasm will add six codes

If you use the codes under Z86.00- Personal history of in-situ neoplasm, you need to be aware of these additions to the 2020 ICD-10 code set:

• Z86.002 Personal history of in-situ neoplasm of other and unspecified genital organ
• Z86.003 Personal history of in-situ neoplasm of oral cavity, esophagus and stomach
• Z86.004 Personal history of in-situ neoplasm of other and unspecified digestive organs
• Z86.005 Personal history of in-situ neoplasm of middle ear and respiratory system
• Z86.006 Personal history of melanoma in-situ
• Z86.007 Personal history of in-situ neoplasm of skin.

Also check the notes under these codes in the ICD-10 tabular list to help improve your coding accuracy. For instance, Z86.002 has a note that the code is appropriate for “Personal history of high-grade prostatic intraepithelial neoplasia III [HGPIN III].”

‘Compatible with,’ ‘consistent with’ qualify as uncertain diagnosis

The ICD-10 official guidelines address coding for uncertain diagnoses, providing different rules for inpatient and outpatient coding. The 2020 update adds some phrases to the list of terms that qualify as uncertain diagnoses under the guidelines, bringing the advice in line with information in a 2005 ICD-9 AHA Coding Clinic^® (vol. 22, no. 3). Both coders and clinicians need to be aware of these rules for documentation and coding.

Watch for the addition of “compatible with” and “consistent with” in Sections II.H and III.C for inpatient admissions to short-term, acute, long-term care and psychiatric hospitals:

If the diagnosis documented at the time of discharge is qualified as “probable,” “suspected,” “likely,” “questionable,” “possible,” or “still to be ruled out,” “compatible with,” “consistent with,” or other similar terms indicating uncertainty, code the condition as if it existed or was established.

Outpatient coders should review Section IV.H for the addition of those same terms:

Do not code diagnoses documented as “probable”, “suspected,” “questionable,” “rule out,” “compatible with,” “consistent with,” or “working diagnosis” or other similar terms indicating uncertainty.

As a final note, this article covers only a small selection of the changes. Your organization will need an up-to-date 2020 ICD-10 resource and easy access to the official guidelines to ensure proper coding. You can download code set updates and current guidelines from the 2020 CMS ICD-10 site or the CDC ICD-10 site.