Policy AHS G2056 (Diagnosis of Idiopathic Environmental Intolerance) is CURRENT (effective 2015-09-18, last reviewed 2025-04-01) and addresses laboratory and diagnostic testing related to idiopathic environmental intolerance (IEI, formerly multiple chemical sensitivity). The policy defines many such tests — including numerous laboratory panels and breath tests — as not meeting coverage criteria and notes that reimbursement unit limits apply for certain CPT codes. Coverage determinations depend on the member's benefit plan and applicable Medicare/Medicaid or other government policies.

IEI (formerly multiple chemical sensitivity) is described as a subjective condition with recurrent, nonspecific symptoms attributed to low-level exposures and without consistent physical findings or laboratory abnormalities. The evidence base for specific diagnostic testing is weak, and professional societies have expressed skepticism or discouraged such testing. Laboratory-developed tests (LDTs) used for some of these assays are regulated under CLIA '88 as high-complexity tests and are not FDA-approved/cleared.

IEI: Idiopathic environmental intolerance (formerly multiple chemical sensitivity) — a subjective condition characterized by nonspecific symptoms attributed to low-level exposures without consistent physical findings or laboratory abnormalities.

LDT: Laboratory-developed test regulated under CLIA '88 as a high-complexity test; these tests are performed in-house by laboratories and are not approved or cleared by the FDA.