If you run benefits at a self-funded employer, GLP-1s are the line item keeping your CFO awake. Ozempic. Wegovy. Mounjaro. Zepbound. List prices north of $1,000 per member per month. Eligibility decisions that hit your plan directly because there’s no carrier risk pool to absorb them. PBM rebates that make it look cheaper than it is. And a rapidly expanding membership of people who would benefit clinically.
Most employers we talk to have made one of three coverage decisions: cover everything (and watch costs balloon), cover nothing (and watch retention drop), or paste together a clinical-eligibility wall that’s painful to administer and porous in practice. None of those are the right answer.
Here’s the actual math, the parts your PBM doesn’t volunteer, and what changes when onsite primary care is in the mix.
The list price isn’t the math
The published WAC (wholesale acquisition cost) on a GLP-1 in the obesity indication is roughly $1,000–$1,350 per month. Most self-funded plans don’t pay WAC — your PBM negotiates a rebate, and the net cost typically lands somewhere between $400 and $700 per member per month after rebates flow through. That’s the number to plug into your model.
But here’s where the rebate math gets ugly: the rebate is usually paid back to the plan months after the claim. So your monthly claims report still shows the gross amount; your CFO sees a $1,000 line item; the rebate trickles back as a credit you’ll forget to reconcile against the original spend. PBMs structure it this way on purpose. Insist your PBM report net cost per fill in your monthly utilization data, not gross. If they can’t or won’t, that tells you something.
The second hidden cost: adherence economics. Half of GLP-1 starters discontinue within 12 months, mostly because of side effects, supply shortages, or out-of-pocket costs that drift past member tolerance. If members start, drop off, restart, drop off again, your plan is paying for the stop-and-start without seeing the durable weight loss that justifies the spend. Continuity of care — the same provider, the same titration plan, the same monitoring — is what keeps members on therapy long enough for the drug to actually work.
The eligibility decision is where the savings live
Most employers focus on the price. The bigger lever is who’s eligible. Three approaches, in increasing order of cost and clinical appropriateness:
Approach 1 — Diabetes only (T2DM): Cover GLP-1s only for members with diagnosed type 2 diabetes. List price typically lower than the obesity indication. Eligibility is straightforward. Cost is contained. This is what most CFOs default to.
Approach 2 — T2DM + obesity with BMI ≥ 35 + comorbidity: Standard medical-necessity criteria. Eligibility roughly 5–10% of a typical mid-market workforce. The clinical case is strong; the financial case is workable if you have a primary care surface that can monitor adherence and manage side effects.
Approach 3 — Open coverage: All adult members at any BMI eligible. Don’t do this. Adverse selection is brutal — every member who’s been waiting for coverage signs up the day eligibility opens. Costs balloon 4–6× the modeled budget within 12 months.
The right answer for almost every self-funded mid-market plan is Approach 2 with active management: clinical eligibility criteria plus a primary care provider who manages titration, monitors adherence, addresses side effects, and pulls members off therapy if they’re not responding. Without that primary-care layer, Approach 2 collapses into either Approach 1 (everyone gets denied) or Approach 3 (clinical reviewers rubber-stamp prescriptions because they don’t have time to follow up).
What an onsite clinic changes
The math changes meaningfully when there’s a clinician on your campus managing GLP-1 therapy directly. Three reasons:
- Adherence climbs. Members who see their NP every 4–6 weeks for titration check-ins stay on therapy longer. The drug actually does what you’re paying for it to do.
- Side-effect management stops becoming an ER visit. Nausea, dehydration, GI complications — managed onsite at no member cost, instead of becoming an urgent-care or ER claim.
- Discontinuation becomes a clinical decision, not a member-experience failure. The clinician decides when a member should come off therapy, not the member quietly running out of refills.
We see Archer-managed populations sustain GLP-1 adherence at roughly 1.5–2× the national benchmark. That’s a direct cost-per-outcome improvement: same drug, same coverage criteria, but the spend produces durable weight loss instead of churning members through the start-stop cycle.
Three questions to ask your PBM and broker this week
If you’re sitting on a GLP-1 coverage decision right now, these three questions surface the real picture:
- “What is our net cost per fill, month over month, for the obesity indication?” Net, not gross. If your PBM reports gross-only, that’s a flag. You’re being shown a number that overstates what you’re paying after rebates.
- “What’s our 12-month discontinuation rate on members who started GLP-1 therapy?” If it’s 50%+, you’re paying for therapy that isn’t working. Adherence is fixable; without measuring it you can’t manage it.
- “What clinical-eligibility criteria are being applied, and who’s reviewing each prescription?” If the answer is “the PBM’s automated prior-auth system,” your eligibility is theoretical. Real management requires a clinician who knows the patient.
GLP-1 coverage isn’t a one-line plan-design decision. It’s a clinical management problem that happens to have a pharmacy line item attached. Self-funded employers who treat it that way save 30–50% versus those who treat it as a pure coverage question.
If you want to model this against your actual claims data, we can — that’s what the cost analysis does. It takes a 20-minute conversation and your trailing-12-month claims export to surface the real net cost, the real adherence pattern, and where onsite primary care would change the curve.