UnitedHealth Stock Hinges on Fixing Commercial Book

UnitedHealth's stock has seen significant growth over the past year, rising about 34% compared to the S&P 500's 21%, driven by a recovery in margins. However, this improvement is not uniform across all business segments, and one area of concern is the company's commercial book.

The Medicare segment has seen improvements, with management expecting the 2026 medical cost trend to come in below its initial estimate of around 10%. This positive trend is attributed to various factors, including benefit design, care management models, network curation, and favorable weather patterns. However, management explicitly states that this improvement does not represent an inflection point.

On the other hand, the commercial side is facing increasing costs, with medical cost trends running modestly above 11%. The independent resolution process under the No Surprises Act is adding incremental trend in 2026 and totals at least 100 basis points of cost. Management characterizes this process as inefficient, noting that dispute filings are heavily concentrated among a small number of provider groups.

As a result, full commercial margin recovery has been pushed past 2027, making it uncertain when the company will achieve its target of strong margins. This delay is attributed to an ineffective arbitration process and increasing costs in office visits and emergency departments.