Biosimilars Are Coming. Will Your Health Plan Capture the Savings?

What if we told you there was a way to take on one of the biggest drivers of pharmacy spend without cutting benefits or limiting access to care? For many employers, that opportunity is already here, and it’s growing.

Specialty drugs account for only about 2% of prescription volume but more than half of pharmacy spend. Biosimilars are bringing lower-cost alternatives to some of the most expensive drugs on the market, with more options entering high-cost specialty drug categories.

The savings opportunity is significant, but it won't happen automatically.

Whether employers actually benefit will depend on what their PBM puts on formulary, how rebates influence those decisions, whether members are transitioned to lower-cost alternatives, and how aggressively the plan manages specialty drugs. 

Getting there requires the right formulary, contract, and plan strategy in place to ensure the member gets the right drug, at the right time, for the right price.  

Why biosimilars matter

Biosimilars are FDA-approved alternatives to biologic medications with no clinically meaningful differences in safety or effectiveness from their reference products. Biologic drugs are complex medications made from living cells, commonly used to treat cancer and other chronic conditions. They're among the most expensive drugs on the market. A UCLA analysis of nearly 15,000 cancer patients found payers saved an average of $3,820 per patient per month when biosimilars were used instead of originator biologics. Biosimilars have delivered more than $81 billion in cumulative savings across the U.S. healthcare system since 2015. Patients also saw meaningful out-of-pocket reductions.

The arrival of biosimilars can also put downward pressure on prices. Brand-name biologic prices have fallen an average of 3.8% annually following biosimilar market entry, while biosimilar prices themselves have declined 12.4% annually.

For self-funded and level-funded employers, OneDigital's Biosimilar Substitution strategy can reduce specialty drug costs by 20–40% in applicable drug categories.

The real opportunity isn't paying less for one drug. Rather, it's building lower-cost alternatives into a deliberate specialty drug strategy.

The next wave is coming

The biosimilar market is moving into its next phase, with more lower-cost alternatives entering high-cost specialty drug categories. In May 2026, the FDA approved the first interchangeable golimumab biosimilars, expanding lower-cost options in the autoimmune category, with additional biosimilars such as new entrants in asthma (Xolair biosimilars) and ophthalmology (Eylea biosimilars) both expected to launch by early 2027, across other high-cost therapies. 

The FDA’s approval of the first interchangeable biosimilar has real formulary and member-experience implications. Interchangeable status means a pharmacist can make this switch at the pharmacy counter without a new prescription in most states, which removes friction. But it does not guarantee your plan captures the savings. Formulary placement and rebate arrangements still decide that, and members should be proactively told before a switch happens, not find out at the pharmacy counter. (Note: timeline for this approval can be accessed here.)

For employers, this means more competition is creating new opportunities to lower specialty drug spend.

Employers shouldn't wait until renewal, or until their PBM brings an opportunity forward, to understand where biosimilars could affect their plan. They should know which high-cost biologics are driving their spend, where lower-cost alternatives are becoming available, and how their PBM intends to respond.

The question is less “What’s coming to market?” and more “Is your plan positioned to capture the savings when it does?”

Five questions to ask your PBM now

A biosimilar being available doesn't mean your plan is capturing the savings. Formulary decisions, rebate arrangements, contract terms, and member transitions all affect what an employer ultimately pays.

Start by asking your PBM:

1. Which biosimilars are we using today, and what savings are they generating for our plan?

2. When a lower-cost biosimilar becomes available, what triggers a formulary change or member transition?

3. Are rebate arrangements influencing which product is preferred?

4. What contractual guarantees do we have around biosimilar adoption, pricing, and savings?

5. Which upcoming biosimilar launches could materially affect our plan in the next 12–18 months?

In some arrangements, rebate economics can favor a higher-cost reference biologic even when a lower-cost biosimilar is available. Without visibility into those incentives, employers may assume their PBM is choosing the lowest-cost option when the actual economics are more complicated.

Availability doesn't equal savings. Plan design, contracting, and execution determine whether your plan captures the value.

Biosimilars are one piece of the specialty drug strategy

Employers shouldn't evaluate biosimilars in isolation. The lowest-cost drug can still become an expensive claim when it's purchased through the wrong channel, administered at a high-cost site, or governed by a contract that limits employer visibility.

That's why OneDigital looks at them as part of a broader pharmacy and specialty drug strategy that can include PBM contracting, specialty pharmacy network management, site-of-care optimization, prior authorization, step therapy, rebate reconciliation, and ongoing claims analysis.

OneDigital's pharmacy consultants operate independently, with no coalitions or financial ties to a specific PBM. That means our recommendations are made on behalf of the employer and the plan. Since 2022, our audit team has recovered more than $4.6 million that PBMs initially indicated they did not owe clients. Employers receive ongoing claims audits, rebate reconciliation, data warehousing, and quarterly clinical analytics to identify opportunities as the market changes.

We have found that employers working with OneDigital's pharmacy consulting team typically achieve 15–35% in pharmacy benefit cost savings through greater transparency, stronger contracting, and proactive clinical management.

Don't wait until renewal to find the savings

The biosimilar pipeline through 2027 creates a meaningful opportunity to put pressure on one of the fastest-growing areas of health plan spend. The employers that benefit most will know what's coming, understand how their PBM will respond, and have the contractual and clinical strategy in place to capture the savings.

Before your next renewal, ask one question:

Do we know which biosimilar opportunities are coming for our plan, and exactly how we're going to capture them?

If the answer isn't clear, it's time to take a closer look.

Connect with a OneDigital pharmacy specialist to review your current formulary, PBM contract terms, and specialty drug exposure.