The Impact of the Medicaid Reimbursement Bump on Influenza Vaccination Rates Among US Teens: Evidence from the National Immunization Survey-Teen 2011-2020

Abstract

Background: Many adolescents do not receive basic preventive care such as influenza vaccinations. The Affordable Care Act (ACA) temporarily increased Medicaid reimbursements for primary care services, including vaccine administration, in 2013 to 2014. The objective of this study is to assess the impact of reimbursement increases on influenza vaccination rates among adolescents with Medicaid.

Methods: This repeated cross-sectional study used a difference-in-difference approach to compare changes in annual influenza vaccination rates for 20,884 adolescents 13 to 17 years old covered by Medicaid with adequate provider-reported data in 18 states with larger extended (>$5, 2013 to 2019) versus larger temporary (2013 to 2014 only) versus smaller reimbursement changes. We used linear probability models with individual-level random effects, adjusting for state and individual characteristics and annual time trends to assess the impact of a Medicaid vaccine administration reimbursement increase on annual influenza vaccination.

Results: Mean Medicaid reimbursements for vaccine administration doubled from 2011 to 2013 to 2014 (eg, from $11 to $22 for CPT 90460). States with smaller reimbursement changes had higher mean reimbursements and higher adjusted vaccination rates at baseline (2011) compared with states with larger temporary and extended reimbursement changes. The reimbursement change was not associated with increases in influenza vaccination rates.

Discussion: Influenza vaccination rates were low among adolescents with Medicaid throughout the study period, particularly in states with lower Medicaid reimbursement levels before the ACA.

Conclusion: That reimbursement increases were not associated with higher vaccination rates suggests additional efforts are needed to improve influenza vaccination rates in this population.

Keywords: Adolescent; Affordable Care Act; Cross-Sectional Studies; Health Policy; Immunization; Influenza; Medicaid.

Figure 1.. Medicaid vaccination administration reimbursements by reimbursement size change and return to baseline reimbursement for Medicaid insured participants.^a

Abbreviation: CPT, current procedural terminology. Notes: ^aA smaller reimbursement increase was defined as a change in 2012–2013 vaccine reimbursement < $5; larger reimbursement increase was defined as ≥ $5. In addition, we identified states with smaller reimbursement increases for both vaccine administration CPT codes (N = 2) (blue line); states with larger temporary reimbursement increases in 2013–2014 only for at least one code (N = 11) (orange line); and states with larger extended reimbursement increases for both codes through at least 2019 (N = 5) (gray line). Top panel: vaccine administration with counseling, CPT 90460; bottom panel: vaccine administration without counseling, CPT 90471.

Figure 2.. Unadjusted trends in influenza vaccination completion by magnitude and duration of reimbursement increase for patients with Medicaid.^a

Abbreviation: CPT, current procedural terminology. Notes: ^aA smaller reimbursement increase was defined as a change in 2012–2013 vaccine reimbursement < $5; larger reimbursement increase was defined as ≥ $5. In addition, we identified states with smaller reimbursement increases for both vaccine administration CPT codes (N = 2) (blue line); states with larger temporary reimbursement increases in 2013–2014 only for at least one code (N = 11) (orange line); and states with larger extended reimbursement increases for both codes through at least 2019 (N = 5) (gray line).