Most GLP-1 coverage decisions get priced off the list price. That is the wrong number. Real-world claims data shows roughly 68% of members quit within a year, usually before durable weight loss sets in. So the money flows to the expensive ramp for the majority who never reach the result. For a self-funded plan of 20 to 250 employees, the figure that should drive your decision is cost per member who actually finishes, not cost per prescription.
Every broker deck on GLP-1 coverage opens with the same slide: a big list price, a scary trend line, a question about whether you can afford it. Wegovy runs about $1,350 a month at list. Zepbound sits a little lower. Multiply by twelve, multiply by a projected number of users, and the answer looks like a reason to say no.
That math is built on an assumption that almost never holds. It assumes the people who start the drug stay on it. They do not.
- The list price is the least useful number in the decision. Net price after rebates is closer to $569 a month, and even that overstates real per-outcome cost.
- About 68% of members who start a GLP-1 for weight loss stop within the first year, per real-world claims data from Prime Therapeutics covering 16 million commercially insured members.
- Clinically meaningful weight loss usually shows up only after a member reaches the maintenance dose, roughly four to five months in, with the full trial result near week 68. Most people quit before they get there.
- The number that matters is cost per member who reaches a durable result: close to $12,900 for one completed year, and north of $40,000 per member still on therapy at two years.
- A self-funded plan of 20 to 250 employees can design around this. A fully-insured plan cannot. That flexibility is the whole point.
The number everyone quotes is the wrong number
Start with what a GLP-1 actually costs a plan. The list price grabs headlines, but no self-funded employer pays list. After manufacturer rebates and plan negotiation, the Institute for Clinical and Economic Review, using net-price data from SSR Health, pegs Wegovy's net cost at about $569 a month, or roughly $6,830 a year. Direct cash-pay programs from Novo Nordisk and Eli Lilly have pushed some doses to the $349 to $499 range, which tells you how much padding sits between the sticker and the true cost.
So the honest starting number is not $16,000 a year. It is closer to $6,830 a year for a member who stays on the drug for twelve straight months.
Here is the catch. Very few members do.
What the discontinuation curve actually looks like
Prime Therapeutics ran the study that should reset this whole conversation. Looking at integrated pharmacy and medical claims for 16 million commercially insured members, Prime tracked everyone who newly started a GLP-1 for weight loss in 2021. One year later, 68% had stopped filling the prescription. A follow-on Prime analysis found only about 1 in 7 members still on therapy at two years, and roughly 1 in 12 at three years.
Read that curve again, because it is the entire story. For every 100 people who start, about 32 finish a year, 14 reach year two, and 8 reach year three. The drug works in the trials. In the field, most members walk away from it long before it delivers.
Why people quit before the benefit arrives
The exits are not random. They cluster early, during the exact window when the drug costs the most and delivers the least.
GLP-1 therapy is a slow build. Dosing titrates upward over the first four to five months to manage nausea and other side effects. In the landmark 68-week STEP-1 trial, semaglutide at the 2.4 mg maintenance dose produced an average weight loss of about 14.9%, against 2.4% for placebo. But that result took the full 68 weeks. Clinically meaningful loss, the 5% threshold that signals the drug is doing its job, generally does not appear until a member reaches the maintenance dose. The weight nadir arrived closer to week 60.
Now overlay the side effects, the injection routine, the cost sharing, and the supply gaps that marked the early market. A member who quits at month three has paid for the expensive titration ramp and captured almost none of the durable benefit. The plan paid too.
That is the core problem. The spend is front-loaded. The results are back-loaded. And most members leave in between.
What employers are actually doing right now
This is not a fringe worry. It is shaping coverage decisions across the market.
In the 2024 KFF Employer Health Benefits Survey, 18% of firms with 200 or more workers said they cover GLP-1 drugs when used primarily for weight loss. Among firms with 5,000 or more workers, that figure reached 28%. Among large firms that do not cover them, 62% described themselves as not likely to add the benefit in the coming year. A 2025 Peterson-KFF analysis of large employers found 64% reported that GLP-1 coverage had a moderate or significant effect on their prescription drug spending.
Employers that do cover the drugs are not writing blank checks. More than half, 53%, attach a condition before approval. In the KFF data, 24% require a member to meet with a dietitian, therapist, or case worker first, 8% require enrolling in a lifestyle program before the first fill, and 10% require staying enrolled in one while on the drug. The market is already trying to gate the ramp. Most plans just are not measuring whether the gate pays off.
The math nobody runs: cost per durable outcome
Here is the calculation that should replace the list-price slide. Take 100 members who start a GLP-1 on your plan. Price them at the real net cost of $569 a month. Then apply the real persistence curve instead of pretending everyone stays.
Roughly 32 members finish a full twelve months. The other 68 quit inside the year. Discontinuers do not stop on day one, they stop somewhere along the ramp, so assume they average five months of paid fills before they walk. The table below is a Benefitra model built on two real anchors: ICER's net price and Prime's persistence data. The assumptions are stated so you can adjust them to your own plan.
| Per 100 members who start | Members | Plan spend (net) |
|---|---|---|
| Finish 12 months on therapy | 32 | $218,560 |
| Quit within 12 months (average 5 months of fills) | 68 | $193,460 |
| Year-one total | 100 | $412,020 |
Now do the division that actually matters. Your plan spent about $412,000, but only 32 members completed a year of therapy. That works out to roughly $12,900 for every member who finished, nearly double the $6,830 sticker. Push it to the durable-results horizon and the number gets sharper. Only about 14 of the original 100 are still on therapy at two years. Carry the spend forward and the cost per member who reaches that two-year mark climbs past $40,000.
The list price told you $6,830 a member. The discontinuation curve says you are really paying $12,900 per completed year and roughly $40,000 per durable result. That gap, between what you budget and what you buy, is the real cost of a GLP-1 benefit. It is money spent on a ramp the majority never finish.
None of this is an argument against covering GLP-1s. It is an argument against pricing them off the wrong number.
Why this hits a 20-to-250 self-funded plan harder
A jumbo employer can absorb a messy persistence curve because the law of large numbers smooths it out. A mid-market self-funded plan cannot. This is where the exposure concentrates.
- Small pools swing hard. On a plan covering 150 employees and maybe 250 total lives, even a handful of GLP-1 starters moves your pharmacy trend. One member who titrates to a high maintenance dose and stays, plus a rotating cast of starters and quitters, can bend PMPM in a single quarter.
- The spend usually lands inside your stop-loss deductible. Specific stop-loss for this size typically attaches somewhere between $50,000 and $150,000. A single GLP-1 user at $6,830 a year rarely pierces that alone, so the drug spend hits your plan assets directly and feeds your aggregate. You carry it, not the reinsurer.
- It shows up at renewal as a laser or an aggregate bump. A persistent high-cost claimant can get lasered at renewal, raising your specific attachment on that member and shifting risk back to you.
- You already carry the industry trend. One analysis by AssuredPartners across 3.7 million member-months found per-member-per-month spend on the top six GLP-1 drugs climbed from $1.43 in 2019 to $24.59 in 2024. That is the current pushing against every mid-market plan, whether or not you formally cover the drugs for weight loss.
The flip side is the opportunity. Because you are self-funded, you own the plan design. You are not accepting whatever the carrier decides to file. You can build the benefit around the curve. A fully-insured group of the same size cannot.
A plan-design framework that prices the curve
If you decide to cover GLP-1s, and there are good clinical and retention reasons to, design the benefit so your dollars follow durability instead of ramps. Five moves do most of the work.
- Price the curve, not the pill. Run the cost-per-durable-outcome model above with your own PBM's net price and your own expected uptake. Bring that number to the renewal conversation, not the list price. It changes what "affordable" means.
- Gate the ramp. Require prior authorization, a documented BMI threshold, and enrollment in a behavioral or lifestyle program before the first fill. More than half of covering employers already do some version of this. It filters out the members least likely to persist before you buy them a titration.
- Tie continued coverage to response. Require a documented weight loss of about 5% by month four to six to keep coverage past titration. That threshold is grounded in the clinical timeline, and it stops the plan from paying maintenance-dose prices for members who are not responding. This single rule attacks the discontinuation curve where it costs the most.
- Contract on net, not on rebate. A formulary chosen to maximize rebate checks can cost more on a net basis. Ask your PBM for net cost per fill and per member, and read the pass-through terms. Rebate optics and net cost are not the same thing.
- Use the self-funded flexibility on purpose. Model the stop-loss interaction, watch your aggregate, and revisit the design every year as net prices and cash-pay programs shift. The market is moving fast, and a benefit you set in 2025 may be mispriced by 2027.
What this means for your next renewal
The point of all of this is not to talk you out of a benefit your employees want. GLP-1s are effective for the members who stay on them, and coverage is becoming a retention question as much as a cost question. The point is to walk into the decision holding the right number.
When your broker or PBM puts up the list price, ask three questions. What is our net cost per fill. What is our expected persistence at twelve months. And what will we actually pay per member who reaches a durable result. If nobody in the room can answer the third question, you are being asked to price a benefit off a number that describes almost none of your members.
A self-funded plan of 20 to 250 employees has the one thing a fully-insured group does not: the ability to design the benefit around the curve instead of the sticker. That is the lever. Pull it deliberately.
Frequently Asked Questions
How much do GLP-1 weight loss drugs really cost a self-funded employer per month?
The list price runs about $1,350 a month for Wegovy and a little less for Zepbound, but no self-funded plan pays list. After rebates, ICER estimates a net cost around $569 a month, or roughly $6,830 a year, for a member who stays on the drug. The number that matters more is cost per member who actually completes therapy, which runs closer to $12,900 for a finished year once you account for the members who quit mid-ramp.
What percentage of people stop taking GLP-1 drugs for weight loss?
Real-world claims data from Prime Therapeutics, covering 16 million commercially insured members, found that about 68% of people who started a GLP-1 for weight loss stopped within the first year. Roughly 1 in 7 remained on therapy at two years, and about 1 in 12 at three years. Discontinuation tends to happen early, often during the titration period, before durable weight loss sets in.
Should a small or mid-size employer cover GLP-1 drugs for weight loss?
There is no single answer, but the decision improves when you price it correctly. Model your real net cost against realistic persistence, not the list price against full-year use for everyone. Then decide whether to cover with conditions, such as prior authorization, a lifestyle-program requirement, and a response-based rule that ties continued coverage to documented weight loss. In the 2024 KFF survey, 18% of firms with 200 or more workers covered these drugs, and most attached conditions.
How do we stop paying for GLP-1 members who quit early?
Tie continued coverage to clinical response. Require a documented weight loss of about 5% by month four to six to keep coverage past the titration phase. That threshold matches when the drug typically starts producing meaningful results. It stops the plan from paying maintenance-dose prices for members who are not responding, which is where the discontinuation curve does the most financial damage.
Does stop-loss insurance cover GLP-1 drug costs?
Usually not in the way employers hope. Specific stop-loss for a 20-to-250-employee plan typically attaches between $50,000 and $150,000. A single GLP-1 user at roughly $6,830 a year rarely reaches that threshold alone, so the spend lands inside your deductible and hits plan assets directly. It also feeds your aggregate, and a persistent high-cost claimant can be lasered at renewal, shifting more risk back to your plan.
Is it cheaper to use a GLP-1 carve-out program?
It can be, if the program is built around persistence rather than access. The stronger carve-out vendors pair the medication with a pre-treatment phase, behavioral coaching, and clinical monitoring, which is designed to improve the odds that a member who starts actually stays and reaches a result. Compare any carve-out on net cost per durable outcome, not on headline discount, and read how it handles members who discontinue.