The picture

Most commercial plans now offer GLP-1 coverage for chronic weight management, but the design choices vary widely. The core trade-off: lower employee out-of-pocket cost drives utilization (3-6x baseline) and total plan cost, but improves engagement and member outcomes. Restrictive design (step therapy, lifetime caps, narrow eligibility) reduces cost but increases administrative burden and member friction. The 2026 winning formulary patterns: BMI ≥ 30 with documented lifestyle attempt; preferred tier 3 (manageable copay $50-150/mo); 24-month renewal requiring ≥ 5% weight loss; no lifetime cap; OSA-with-obesity Zepbound pathway carved out separately.

Key statistics

Average utilization rate (members with eligible BMI)

12-18%

Typical PMPM cost increase post-launch

$8-15

Members reaching 5% weight loss at 12 months

~68%

Renewal continuation rate at 24 months

~40%

Takeaways

BMI ≥ 30 (or ≥ 27 with comorbidity) is the standard eligibility floor.
Tier 3 (preferred brand) with $50-150 copay balances access and cost.
Annual renewal with weight-loss benchmark (5% body weight) prevents indefinite high-cost use.
Carve out OSA-with-obesity Zepbound — usually approves easier and serves different member need.
Step therapy through Saxenda or phentermine adds friction without meaningful savings — skip it.

GLP-1 benefit design

GLP-1 benefit design