Your Mail Order Mandate Is Saving the Plan Money. It's Costing Your Employee More.

When your plan mandates mail order for maintenance medications, it's the employer's decision, not the PBM's. That distinction matters. It's your employees who feel the consequences.

Here's the situation. A member has been filling a maintenance medication locally using a manufacturer coupon. It's been working. Then the plan's mail order requirement kicks in, and the coupon disappears. Their out-of-pocket cost jumps. They're frustrated, and they have a right to be.

This happens more than employers realize. And it rarely comes up when the PBM is pitching you on mail order savings.

Who actually requires mail order: the employer or Express Scripts?

The employer requires it. Express Scripts administers it. That's an important separation most employees, and many HR teams, never make.

The plan design document dictates that after a certain number of retail fills, ongoing maintenance medications must go through mail order. The PBM pitches this to the CFO as a savings mechanism. Mathematically, it often is. But the savings go to the plan. The member's experience is a different calculation entirely.

What makes this more complicated is that Express Scripts operates its own mail order pharmacy, separate from its specialty pharmacy Accredo. The PBM both manages the benefit and fills the prescription. That's a vertically integrated model. The incentive to steer volume to the captive pharmacy is baked into the structure.

Why do manufacturer coupons stop working at mail order?

Manufacturer coupons are designed for retail pharmacy transactions. Most won't process through a mail order pharmacy. Express Scripts' mail order operation is no exception. The member who relied on a coupon to make a brand-name medication affordable suddenly faces the full plan cost-sharing structure. That's often significantly higher.

This is a genuinely overlooked consequence of mail order mandates. The plan models savings assuming members fill through mail order at contracted rates. It doesn't model what happens to members who were using external assistance to reduce their cost.

Those members fall through the gap.

The best immediate option for that member is to check GoodRx or a similar cash-pay tool. In many cases, paying cash at a local pharmacy without running it through insurance beats the mail order net cost, coupon or not. Check before assuming mail order is the only path.

Actual costs vary by medication, plan tier, and geographic market. Use these ranges as a starting framework, not a guarantee.

Can the employer override the mail order requirement?

Yes. The employer absolutely has the authority to grant an exception or remove the mandate entirely. Whether they will is a different question.

For smaller employers, this is straightforward. Amend the plan document, communicate the change, move on.

For large employers, especially those with 5,000 or more employees, it gets complicated fast. Many PBM contracts tie financial performance guarantees to mail order utilization rates. If the plan was promised a per-member savings guarantee contingent on a certain percentage of maintenance fills going through mail order, granting exceptions may void part of that guarantee.

That's a real financial consideration. So is a workforce that feels the plan is working against them. Both belong in the conversation.

What does the PBM's conflict of interest mean for your savings claims?

When the entity managing your pharmacy benefit also owns the pharmacy filling prescriptions, you need independent verification of what you're actually saving. This isn't hypothetical risk. It's documented.

A government audit found Express Scripts overcharged the American Postal Workers Union Health Plan and FEHBP nearly $44.9 million by failing to pass through contracted prescription drug savings over contract years 2016 through 2021. That overcharge went undetected until an independent audit found it.

A separate OPM Office of Inspector General audit examined Express Scripts' performance on the Compass Rose Health Plan covering contract years 2017 through 2022, again focused on performance guarantees and compliance. And a House Oversight Committee report found that Express Scripts and the other two dominant PBMs have begun creating foreign corporate entities to obscure operations and avoid proposed transparency reforms.

According to NCPA-cited market data, nearly 80% of equivalent prescription claims in the U.S. flow through just three PBMs. That concentration means your plan has limited alternatives. It doesn't mean you have to accept the savings figures at face value.

If you've built a mail order mandate into your plan design to capture savings, you need contractual pass-through guarantees and periodic third-party audits of mail order claims pricing. Otherwise you're modeling savings that may not be arriving. Our article on PBM rebate pass-through contract language covers what that protection actually looks like in writing.

What should you do right now?

If a member contacts you about a mail order requirement blocking their coupon, point them to GoodRx first. It's not a perfect answer, but it's an immediate one. It may actually reduce their cost below what either the coupon or the mail order copay would have been.

At the plan level, ask your broker whether your current mail order mandate has a financial performance guarantee attached to it. Find out what conditions void it. Know that before an employee requests an exception.

If you haven't had an independent audit of your mail order claims pricing in the last two years, schedule one. The OPM audits didn't find problems by trusting the PBM's reporting.

For a broader look at how PBM contract structures create these blind spots, see our piece on the three PBM contracts you probably have and only know about one.

Frequently asked questions

Is the mail order pharmacy requirement a federal rule or an employer decision?

It's an employer plan design decision. Federal law doesn't require maintenance medications to be filled through mail order. The employer, typically at the recommendation of the PBM during contract negotiations, builds that requirement into the plan document. That means the employer can also remove or modify it.

Why won't a manufacturer coupon work at an Express Scripts mail order pharmacy?

Manufacturer coupons are structured for retail pharmacy point-of-sale transactions. Most aren't accepted by mail order pharmacies, including Express Scripts' captive mail order operation. The member has to absorb the full cost-sharing under the plan design, which is often higher than what they were paying with the coupon at retail.

How can a member find a lower cash price outside the plan?

GoodRx, Mark Cuban's Cost Plus Drugs, and similar cash-pay platforms can sometimes offer prices that beat both the mail order copay and the manufacturer coupon. The member pays out of pocket without running it through insurance, which means it won't count toward their deductible. For some medications the savings are significant enough to make that trade-off worth it. Check the Benefits Blake glossary for definitions of how these cash-pay tools interact with plan cost-sharing.

What is a financial performance guarantee in a PBM contract, and why does it matter here?

A financial performance guarantee is a contractual commitment from the PBM that the plan will achieve a specified level of savings. It's often tied to metrics like mail order utilization rates. If the plan doesn't hit those utilization targets because exceptions are granted, the PBM may reduce or eliminate the guaranteed savings. Large employers should know what metrics their guarantees are tied to before approving any individual exceptions. Our article on best-in-class transparent PBM contracts outlines what those terms should and shouldn't include.

Has Express Scripts been found to withhold savings that should have gone to the plan?

Yes. A government audit found Express Scripts overcharged the American Postal Workers Union Health Plan and FEHBP nearly $44.9 million by not passing through all contracted prescription drug savings for contract years 2016 through 2021. That overcharge was identified through an independent audit, not through the PBM's own reporting. Plan sponsors with mail order mandates should require independent periodic audits of mail order claims pricing as a contract condition.