Contact or Irritant Dermatitis is one of the most difficult diagnosis to make with respect to identifying the offending agent.  The list of ICD-10 codes that classify the various types of contact dermatitis is long.  In order to specify the exact type of Allergic Contact Dermatitis, the use of patch testing is the quickest way to ascertain the source.

Patch testing is billed using CPT codes 95044.   Below are listed the documentation requirements as well as the ICD-10 codes that support the billing of this service.

DOCUMENTATION REQUIREMENTS

1. 1. Prior to performance of patch testing, there must be evidence in the medical record that a history has been obtained indicating the possible presence of a rash, or itching, severe redness that won’t go away, a burning sensation, just to name a few.
   2. This history should support that attempts to narrow the area of investigation was taken so that the minimal number of necessary skin tests might deliver a diagnosis.
   3. The history should support that the selection of the number of patch tests was based on the patient specific history and physician examination.
   4. The medical record must indicate which patch test(s) were used, the interpretation(s), and measurement (in mm) of reaction size of both wheal and erythema response, for example.

COVERAGE

Patch testing is covered when clinically significant symptoms exist and conservative therapy has failed.  Patch testing includes the performance, evaluation, and reading of cutaneous and mucous membrane testing.
The MUE limit for 95044 is 80 per day, per patient.  The Medicare allowable for one unit is $5.56 per test although I have seen payments as high as $15.00 per allergen.  The patch test kit usually contains 24 tests. Therefore, the code is billed in 24 units on the CMS-1500 claim form. The patch test(s) are billed on the day the patches are applied.

An E/M code is billed when the results are determined.
The patch test code can be provided under the incident to criteria. This means that the application of the patch tests can be performed by the following as long as there is a provider on-site:

• Medical Assistant
• Nurse
• Technician
• PA or NP

Evaluation and management (E/M) codes can be reported with patch test only if:

1. A significant, separately identifiable service is performed.
   If E/M services are reported, modifier 25 should be utilized.
2. Since there is no postoperative period, an E/M visit is billed when the results are read.
   The bilateral rules do not apply.
   The multiple surgery rule does not apply.

ICD-10 GUIDELINES

CODES SUPPORTING MEDICAL NECESSITY FOR PATCH TESTING

Update:  For added clarification, this article was updated on 4/18/23.