Effective oncology provider networks under Medicare Advantage plans in 2015-2019.

191 Background: Medicare is the primary payer for older adults with cancer, and its administration is increasingly privatized. Medicare Advantage (MA) plans—privately administered alternatives to Traditional Fee-for-Service (FFS) Medicare, now cover more than half of Medicare beneficiaries. MA plans commonly restrict provider networks, which may limit access to specialists. However, little is known about the effective oncology provider networks in MA, based on realized healthcare utilization among cancer patients. Methods: Using the SEER-Medicare linkage, we characterized oncology provider networks in 2015-2019 using a cohort of Medicare beneficiaries diagnosed with a first primary cancer (breast, lung, colorectal, prostate, pancreas, bladder, blood, or kidney). MA coverage was assessed monthly from 2015 to 2019 for each beneficiary to attribute service claims to specific MA plans. Two primary outcomes were evaluated among MA plans on the contract-year level: (1) the percentage of oncology providers (identified by Tax Identification Numbers [TINs]) who billed under a given MA plan, relative to all oncology providers who treated FFS beneficiaries in the same county; and (2) whether any services under the MA plan were billed by an NCI-designated cancer center. Descriptive statistics for these two metrics were reported overall and by year, separately for regular MA plans and special-needs plans (SNPs) – specialized MA plans serving beneficiaries with high care coordination needs (e.g., dual eligible or those with chronic conditions). Results: We identified 56,623 regular MA plan-year observations across 1,087 counties, and 37,162 SNP plan-year observations across 1,034 counties. From 2015 to 2019, the average number of regular MA plans and SNPs per county increased from 9.6 to 11.3 and from 7.1 to 11.3, respectively. The average percentage of in-network oncology providers was 11.7% (SD = 14.3%) across regular MA plans and 10.1% (SD = 12.2%) across SNP plans, which were relatively stable over the study period. (Table) Additionally, 31.0% of regular MA plans and 25.8% of SNPs had any claim associated with an NCI-designated cancer center. Conclusions: Despite increasing enrollment in MA plans, effective oncology provider networks remained limited and stagnant from 2015 to 2019 in SEER regions. Restricted access to NCI cancer centers under MA plans has implications for access to innovative treatments and cancer outcomes; evaluation of how plan features, including provider networks, affect cancer care delivery is warranted. Effective oncology provider networks, 2015-2019. Total 2015 2016 2017 2018 2019 Percent in-network oncology providers, Mean (SD) Regular MA 11.7 (14.3) 12.2 (13.9) 12.0 (13.7) 11.6 (14.3) 11.8 (15.2) 11.0 (14.1) SNP 10.1 (12.2) 9.4 (11.1) 9.4 (11.4) 9.5 (11.1) 10.0 (12.9) 11.3 (13.1) Any NCI-designated cancer center, % Regular MA 31.0 29.4 31.1 31.2 31.2 31.6 SNP 25.8 23.4 22.8 25.5 26.3 28.5