Fewer than half of employers under 1,000 staff now use a Big Three PBM

The statute's start dates turn a 2027 renewal into a decision about timing. The pass-through rules in CAA 2026 apply to contracts entered into, renewed or extended for plan years beginning on or after August 3, 2028 ^[8]. For a calendar-year plan, that means January 1, 2029 ^[8]. Because the rules attach at renewal, a multi-year contract signed in the 2027 cycle may not fall under them until it is next renewed or extended, HCAmag reported ^[10]. Take a calendar-year plan that signs a three-year term starting in January 2028. Its next renewal is for the plan year beginning January 2031, so it runs through 2029 and 2030 without statutory pass-through ^[24].

None of the law's requirements is in force yet ^[7]. A buyer can still write the statute's terms into a 2027 contract, and HCAmag reported that rebate terms, audit rights and compensation reporting are already on the table in current negotiations ^[11]. The trade-off is between keeping today's deal for longer and coming under the statute sooner. A shorter term, or one that renews for a 2029 plan year, gets a calendar-year plan to the January 2029 date ^[8].

The National Alliance figures show small employers moving fastest. Big Three use among employers with fewer than 1,000 staff fell 25.9 points in a year ^[22], against 9.1 points across all respondents ^[21]. The small-employer group went from 6.3 points above the overall share in 2025 to 10.5 points below it in 2026 ^[23]. In my view that shows small buyers have alternatives they will use. The reporting does not say how many of the 408 employers and purchasers surveyed in May and June 2026 had fewer than 1,000 staff ^[2], or what terms the switchers obtained.

A skeptic would say the incumbents are already conceding, so there is little to gain by moving. The Mintz update records a pricing change at each of the three ^[12]. Of those announcements as reported, only Express Scripts has a date for all clients: its rebate-free model reaches fully insured clients in 2027 and becomes standard for everyone by 2028 ^[14]. CVS Caremark has signaled a direction ^[15]. A promise dated 2028 does not alter a contract signed in 2027 unless the contract says so. Large employers are timing their own moves to the same window. In a Business Group on Health survey of 127 large employers, 32 percent plan to bring in a transparent or next-generation PBM arrangement in 2027, and 47 percent more are considering one for 2028 or 2029 ^[16]. Together, 79 percent are offering or weighing the change by 2029 ^[25].

Some alternatives bypass the PBM entirely. GoodRx's Employer Direct, launched in February 2026, lets employers subsidize manufacturer cash prices at the pharmacy counter ^[17]. Eli Lilly's Employer Connect, which started in March 2026, makes Zepbound available at a $449-a-month list price through a pharmacy network set up for the program ^[18]. More than 15 independent program administrators support that network ^[18]. Coverage of these drugs carries its own risk: Sun Life data links GLP-1 coverage decisions to catastrophic claim risk, according to HCAmag ^[26].

I think term length matters more this quarter than which vendor wins the business. For a calendar-year plan, a contract signed in the 2027 cycle sets the rebate terms for 2028 whatever its length, and under a three-year term it sets them through 2030 ^[24].