United States Billing Practices
Coding Guide (Patch Testing)

Note: The information provided is believed to be current and correct as of May 1st, 2004, however, it is intended to be used only as a guide to the steps required for billing patch testing services rendered by a physician

1. Current Procedural Terminology (CPT) Codes

• For the patch test application use CPT Code 95044 (patch or application tests). Specify the number of tests in field 24G of the CMS (formerly HCFA) Form1500. Each test allergen is a separate billing unit. The total charge is entered in field 24F and is the product of the number of tests and the unit charge per test. In the example shown below, assuming the use of all tests in the North American Series (45 tests), 45 units would be entered in field 24G. Applying a hypothetical unit charge of $12 per test, a fee of $540 would be entered in field 24F of Form 1500.



• In addition to Code 95044, a separate Evaluation and Management (E/M) code may be billed for the office visit during which the patch test is applied. For new patients, use codes 99201-99205 in field 24D. The CPT modifier 25 (significant, separately identifiable E/M service by same physician) is applied to the E/M code for the visit during which the patch test application occurs. This is entered in field 24D, as shown in the example.



• A separate E/M code is billed for each follow up visit to perform readings (codes 99211-99214). If the reading is taken by a nurse or assistant, use Code 99211; the physician must be available in the office, even if he/she does not see the patient. In the case of the final reading and definitive diagnosis, which may involve a detailed examination, medical decision making of moderate complexity, discussion of results with the patient and counseling on alternative treatments, etc., the appropriate code is related to the time value (see below).

2. International Classification of Diseases, (ICD) Codes

3. Form CMS 1500, Field 24 - Example

The fees used in this example are for illustration only. They do not reflect values which will apply to all practices; nor are they intended to reflect actual carrier reimbursement levels. Similarly, the choice of E/M codes will depend upon the actual services performed, including complexity and time spent (see table above). The number of units entered in field 24G and the charges in 24F depend upon the number of tests performed. The example assumes use of all 45 tests included in the North American Series. Place of Service (POS) Code 11 is used in field 24B to designate office visits. This example shows follow up readings at 48 hours (in the example, performed by nurse or other staff) and a final reading at 72 hours. Documentation should reflect the level of care, medical necessity, and time spent (see, American Academy of Dermatology; Coding & Documentation Manual: A Guide for Dermatology Practices).