---
type: source
title: "PHTI December 2025 Employer GLP-1 Approaches Report + Mercer 2026: Large Employer Coverage ≠ Small Employer Coverage — Resolving Session 31 Scope Mismatch"
author: "Peterson Health Technology Institute / Mercer"
url: https://phti.org/wp-content/uploads/sites/3/2025/12/PHTI-Employer-Approaches-to-GLP-1-Coverage-Market-Trend-Report.pdf
date: 2025-12
domain: health
secondary_domains: []
format: report
status: processed
processed_by: vida
processed_date: 2026-04-30
priority: high
tags: [glp-1, employer-coverage, behavioral-mandate, large-employer, small-employer, scope, parity, obesity]
intake_tier: research-task
extraction_model: "anthropic/claude-sonnet-4.5"
---

## Content

This archive resolves the Session 31 branching point: is the 34% behavioral mandate figure (Session 30) vs. 2.8M covered lives decline (Session 31) a scope mismatch or a divergence?

**PHTI December 2025 Report:**
- 34% of employers requiring behavioral support as GLP-1 coverage CONDITION (up from 10% — 3.4x in one year)
- Survey methodology: employer-sponsored plans — the PHTI report covers primarily LARGE employers (those with sufficient scale to administer condition-based coverage)
- "About half of all employers require members to meet certain clinical criteria above the FDA label" — applied to plans that have CHOSEN to cover GLP-1s at all

**Mercer 2026 data:**
- 90% of LARGE employers plan to continue GLP-1 coverage through 2026
- 86% of MID-MARKET employers plan to continue
- Insurers offering small employer plans restricting obesity GLP-1 coverage starting January 1, 2026

**The scope mismatch resolution:**
The two data points measure DIFFERENT populations:

Population A (PHTI behavioral mandate 34%, Mercer 90% continuing):
- Large employers (typically 500+ employees or self-insured)
- These employers have ALREADY chosen to cover GLP-1s
- Behavioral mandate means: "we cover, but you must participate in lifestyle support"
- Adding conditions to coverage they're keeping → cost management, not elimination

Population B (DistilINFO 3.6M → 2.8M covered lives decline, Session 31):
- Health system-employed populations (Allina, RWJBarnabas, Ascension)
- State government employees (4 states withdrawing coverage)
- Kaiser California Medicaid/commercial (eliminating, not adding conditions)
- Regional and small-group insurers restricting small employer plans

**Conclusion: SCOPE MISMATCH, not DIVERGENCE**
These are not contradictory trends in the same population. They are:
- Large employer sophisticated response: keep coverage, add behavioral conditions (PHTI data)
- Health system + state employer + small group response: drop coverage entirely (DistilINFO data)

The net population-level picture: more sophisticated management for those who retain access; fewer people with access overall (3.6M → 2.8M covered lives = 22% decline in covered lives for weight management).

**Additional scope finding (small employers):**
- Mass General Brigham Health Plan example: small employers (under 50 subscribers) no longer offered GLP-1 obesity coverage as of January 1, 2026
- Employers with 50+ subscribers offered GLP-1 obesity coverage as an add-on option

## Agent Notes

**Why this matters:** This resolves the most important open question from Session 31 (Direction A: scope mismatch investigation). The finding: the two data points are measuring different populations. This is NOT a KB divergence — it's a scope qualification that both claims need. The net access picture is worsening (22% decline in covered lives) even as the sophistication of coverage management at large employers increases.

**What surprised me:** The threshold for being in the "sophisticated large employer" bucket appears to be much lower than I expected — 50 enrolled subscribers for Mass General Brigham's plan. Many mid-size companies (think: local restaurants, contractors, retail) fall below this threshold and face the small employer restriction.

**What I expected but didn't find:** A breakdown of what percentage of total covered lives are in large employer vs. small employer plans for GLP-1. Without this, we can't calculate the net access impact. The 3.6M → 2.8M figure is the best population-level proxy.

**KB connections:**
- Resolves Session 31 branching point (Direction A confirmed — scope mismatch)
- Enriches the GLP-1 access inversion framing: coverage is bifurcating by employer size, not just by payer type
- The 22% covered lives decline (3.6M → 2.8M) is the net population-level result
- Connects to the Medicaid layer (California, 4 states cutting) → total population-level access trajectory is downward

**Extraction hints:**
- This is primarily a musing clarification (resolves the branching point) rather than a new KB claim
- IF extracted: "GLP-1 obesity coverage is bifurcating by employer size — large self-insured employers are keeping coverage with behavioral conditions while small group insurers are withdrawing coverage entirely, with the net population-level effect being a 22% decline in covered lives"
- Scope qualifier: "covered lives for weight management indication" (GLP-1 for diabetes remains covered)

**Context:** PHTI (Peterson Health Technology Institute) is a nonprofit health technology assessment organization. Mercer is a benefits consulting firm that surveys large employers annually. Both data sources are credible but represent different employer populations.

## Curator Notes (structured handoff for extractor)
PRIMARY CONNECTION: GLP-1 covered lives decline + behavioral mandate claims (both Sessions 30-31)
WHY ARCHIVED: Resolves the Session 31 branching point (scope mismatch, not divergence). The large employer vs. small employer split is the scope qualification that both claims need. The net population-level direction (22% decline in covered lives) is the summary statistic.
EXTRACTION HINT: Use as scope qualification evidence rather than standalone claim. The key insight: what looks like a contradiction (behavioral mandates growing + covered lives declining) is actually two trends in different populations. The extractor should note this when reviewing Sessions 30-31 sources.
