Insurance Formularies Holding Up Lower-Emission Asthma, COPD Inhalers

Commercial insurance formularies have posed a barrier to cutting greenhouse gas emissions from metered-dose inhalers used to treat asthma and chronic obstructive pulmonary disease (COPD), a study showed.

Lower-emission versions — dry powder inhalers and soft mist inhalers — had less coverage and less often were covered on tier 1 or 2 without prior authorization or step therapy as compared with more polluting metered-dose inhalers, Soko Setoguchi, MD, DrPH, of the Rutgers RWJBarnabas Center for Climate, Health, and Healthcare in New Brunswick, New Jersey, and colleagues reported in JAMA Network Open.

For short-acting β2-agonists (SABAs), 66.4% of plans only covered a metered-dose inhaler without any hydrofluoroalkane propellant-free option.

And whereas over 99% of the 31,219 commercial plans examined covered at least one inhaled corticosteroid inhaler (ICS) and combination ICS-long-acting β2-agonist inhaler (LABA), propellant-free versions were covered by 89.5% and 82.6%, respectively.

“Meaningful reductions in inhaler-related emissions in the U.S. will require lower formulary barriers for propellant-free options while preserving [metered-dose inhaler] access when clinically indicated,” the researchers argued.

Their prior study showed similar findings among Medicare plans for these three classes that together account for nearly all inhaler-related greenhouse gas emissions in the U.S., which together add up to the equivalent of about half a million gasoline-powered passenger vehicles driven for 1 year. “What was distinctive about private insurance coverage was the numerous barriers that existed, despite it generally offering better coverage than Medicare,” Setoguchi and co-author Ashwaghosha Parthasarathi, MBBS, also of Rutgers RWJBarnabas, said in an email.

The formulary structure for environmentally friendly inhalers is the major barrier to patients’ access, they said.

“It is not the availability,” Setoguchi and Parthasarathi said. “Many low-emission inhalers are approved and available in the U.S. market, but insurance coverage favors higher-emission metered-dose inhalers for commonly used SABAs, ICS, and their combination.”

“A clinician might identify an environmentally friendly inhaler suitable for their patient, only to discover that the patient’s insurance does not cover it or requires extra steps to obtain it,” they added.

Their study utilized the MMIT Coverage Search to identify commercial plan formularies across the 50 states and Washington, D.C., in May 2026. The analysis reflected plan-level coverage rather than individual patient plan enrollment, nor did it assess actual out-of-pocket costs, coverage exceptions, prescribing or dispensing patterns, or clinical appropriateness of device switching for individual patients. Another limitation was inability to distinguish some generic products in the source data.

Metered-dose inhalers in all three medication categories had near-universal coverage on tier 1 or 2 of the insurers’ formularies without prior authorization or step therapy (SABAs, 99.2%; ICS, 93.8%; and ICS-LABAs, 88.7%). For propellant-free versions, those rates were only 7.8% for SABAs, 61.8% for ICS, and 52.2% for ICS-LABA combinations.

The Veterans Health Administration system has offered a pathway for national improvement. Its inhaler-related emissions dropped by 68% from 2008 to 2023 on an annual basis, in part because of a cost-motivated 2021 VA formulary renegotiation that replaced budesonide-formoterol metered-dose inhalers with the lower-emission fluticasone-salmeterol dry-powder inhalers as the preferred ICS-LABA inhaler.

However, a previous VA study showed that the switch to a dry-powder inhaler came with a small increase in emergency and hospital care, suggesting a need for careful roll-out of clinical evidence-based changes.

Setoguchi’s group pointed to European prescribing guidance as “a more patient-centered approach, promoting lower-emission inhalers through patient review and shared decision-making rather than blanket substitution,” leading to metered-dose inhalers accounting for fewer than 50% of inhalers overall.

“For U.S. payers, coverage design could support clinically appropriate lower-emission inhaler use by placing at least one propellant-free option per class on preferred tiers, minimizing utilization management for those options, and increasing transparency to help employers and purchasers align benefit structures with access and sustainability goals,” Setoguchi and colleagues wrote.