The share of employer-sponsored health plans using one of the three largest pharmacy benefit managers (PBMs) in the US fell nine points in a single year, from 63.4 percent in 2025 to 54.3 percent in 2026. The movement was almost entirely driven by employers with fewer than 1,000 employees. That finding comes from the 2026 Pulse of the Purchaser survey, published by the National Alliance of Healthcare Purchaser Coalitions (National Alliance).
The National Alliance survey drew on 408 employer and purchaser responses fielded in May and June through its member coalition network. It is a non-probability sample of employers engaged enough to participate in a healthcare purchaser coalition. The findings represent the views of that group rather than all US plan sponsors.
The Big Three PBMs are CVS Caremark, Express Scripts/Evernorth, and OptumRx. Among employers with fewer than 1,000 employees, the share naming one of those three fell 26 points, from 69.7 percent in 2025 to 43.8 percent in 2026. Among mid-size employers (1,000 to 9,999 employees), the share was flat at roughly 51 percent in both years. Among the largest employers (10,000 and above), it edged down from 75 percent to 72.1 percent, a change the report treats as directional rather than statistically meaningful.
National Alliance President and CEO Shawn Gremminger said the Big Three are better equipped to handle the volume of claims associated with large employers, a primary reason large plan sponsors are less likely to move. That assessment appeared in a Bloomberg Law report on the survey. The National Alliance data support it.
Among Big Three clients still considering a switch, intent rises with employer size: 47.4 percent among those under 1,000, 57.4 percent among those with 1,000 to 9,999 employees, and 60.4 percent among those with 10,000 or more. Large employers are the most interested in switching and the slowest to act. The report attributes that gap to the scale of the decision and the use of formal procurement cycles requiring time to evaluate pricing, operations, and member impact.
Of the 27 employers that changed PBMs in the past year, 20 now use a non-Big Three PBM and seven use one of the Big Three. The report notes this shows only where employers are now, not which PBM they left. Employers currently using a non-Big Three PBM were more than twice as likely to have changed in the past year (24.4 percent) as current Big Three clients (11.3 percent).
The contract transparency data add context to the switching figures. Among Big Three clients, 23.4 percent said they were not sure what was in their PBM contracts. The rate among employers using other PBMs was 11.7 percent.
The gap holds across specific contract protections. On no-spread-pricing terms, 21.3 percent of Big Three clients reported having that protection, against 38.3 percent of non-Big Three clients. On disclosure of affiliated entities, the figures were 18.8 percent versus 36.8 percent.
On lowest-net-cost formulary design, the rate was 17.4 percent among Big Three clients and 34.2 percent among those using other PBMs. Rebate pass-through was the one protection where Big Three clients reported roughly equal terms, at 56.7 percent versus 49.2 percent. The report notes that non-Big Three employers may have switched specifically to obtain stronger contract terms, which introduces a selection effect in the data.
Fiduciary concern tracks the same pattern. Among Big Three clients, 36 percent reported concern about the integrity of PBM administration, against 12.9 percent of employers using other PBMs. On the reasonableness of PBM compensation, the rates were 34.8 percent and 12 percent.
That concern has external grounding. A January 2025 second interim staff report from the Federal Trade Commission (FTC) found the Big Three PBMs and their affiliated specialty pharmacies generated more than $7.3 billion in revenue from dispensing specialty generic drugs in excess of estimated acquisition costs between 2017 and 2022. The FTC found that PBM-affiliated pharmacies received 68 percent of the dispensing revenue generated by specialty drugs in 2023, up from 54 percent in 2016.
Employers without full pharmacy claims access were more than twice as likely to express concern about PBM compensation and administration as those with full access. The report describes this as an association rather than a proven causal relationship.
The Consolidated Appropriations Act, 2026 (CAA 2026), signed on February 3, will require PBMs to pass through 100 percent of rebates and related remuneration to ERISA-governed group health plans. It also eliminates spread pricing and requires detailed semiannual drug pricing and compensation disclosures to plan sponsors. Analysis from law firms Ogletree Deakins and Morgan Lewis confirms most substantive provisions take effect for calendar-year plans on January 1, 2029.
The CAA 2026 applies automatically to self-funded plans with 100 or more participants. Fully insured plans must opt in annually. Plan sponsors negotiating or renewing PBM agreements now, which typically run three years, should consider incorporating disclosure and pass-through requirements ahead of 2029, according to Morgan Lewis.
Support for PBM reform has grown alongside the market shift. The National Alliance survey found 87.6 percent of employers rated PBM reform as very or somewhat helpful for addressing healthcare affordability, the highest of any policy option tested and up roughly 20 percentage points from 2023.
For benefits brokers advising small and mid-size plan sponsors, the data point to a specific opportunity. Employers under 1,000 employees are already changing PBMs at a rate larger employers are not, amid concerns about contract transparency, spread pricing, and claims data access.
The CAA 2026 will give qualifying self-funded plans new disclosure rights in 2029. Brokers who begin PBM contract reviews ahead of that date are better placed to help clients use those rights when they arrive.
