Tiered Physician Network Plans and Patient Choices of Specialist Physicians.

Importance: Tiered physician network (TPN) health plans sort physicians into tiers based on their cost and quality, and patients pay lower copays for visits with physicians in the lower-cost and better-quality tiers. When the plans are first introduced, they lead patients to seek care from higher-value physicians.

Objectives: To examine whether TPNs are associated with patient choice of physician when the plans have been in place for 8 to 12 years and whether there are inequities in patient out-of-pocket costs associated with inequities in access to physicians in lower-copay tiers.

Design, Setting, And Participants: This cross-sectional study comprising 46 645 physicians and 585 399 patients in TPNs, including 54 683 patients who had a new patient visit with a physician in a TPN, used health insurance claims data from a large employer purchaser from July 1, 2014, to June 30, 2019. Statistical analysis was performed from November 2020 to August 2023.

Exposure: Evaluation and management visit with a physician in a TPN.

Main Outcomes And Measures: Main outcomes were new patient market share per physician-carrier-zip code-year, distance from centroid of patient zip code to centroid of zip code of nearest low- or medium-copay physician, and mean TPN physician office visit copay per patient. A regression discontinuity design was used to estimate the association of a physician's tier ranking, and a difference-in-differences analysis was used to estimate the association of copayment differences across tiers with market share among new patients. Equity in access was measured by comparing travel distance to the nearest physician in a low-copay or medium-copay tier and mean copayments across patient incomes.

Results: The main analysis sample included 46 645 physician-carrier-zip code-year observations, 9506 (20.4%) of which were in the low-copay tier, 31 798 (68.2%) in the medium-copay tier, and 5341 (11.5%) in the high-copay tier. The 54 683 new patients in the sample had a mean (SD) age of 46.4 (16.7) years and included 33 542 women (61.3%). There was no association of having a worse tier ranking (0.045 percentage points [95% CI, -0.058 to 0.148 percentage points]) or of copayment differences between tiers (0.001 percentage points [95% CI, -0.002 to 0.004 percentage points]) with physician market share among new patients. The patients with the lowest income paid slightly lower mean (SD) copayments for office visits to a TPN physician than the patients with high income ($48.08 [$16.42] vs $51.59 [$16.79], a 6.8% difference).

Conclusions And Relevance: In this cross-sectional study of TPN health plans, there was no association between physician tier ranking and physician market share among any group of patients. These findings suggest there are limitations in TPNs' steering of patients toward high-value physicians. These plans were not associated with exacerbated health inequity in this setting.