# Looking Under the Hood of MA

> **NIH NIH P01** · HARVARD MEDICAL SCHOOL · 2020 · $330,145

## Abstract

Project Summary/Abstract
Compared to traditional Medicare (TM), Medicare Advantage (MA) health plans have more flexibility in benefit
structure, network contracting, and ability to deliver coordinated and integrated care. In addition to these
opportunities for potentially improving patient care, the MA program has established a rebate mechanism for
passing through efficiencies to enrollees in the form of enhanced benefits. MA may therefore offer greater
value to Medicare and its beneficiaries than TM. However, MA plans also engage in costly “gaming” of the risk-
adjustment system without improving performance that adds to government expense. The proposed project will
leverage two new sources of data. The first are encounter data submitted by MA plans, which recently became
available and will be released for subsequent years on a regular basis. The second is the Risk Adjustment
Payment System (RAPS) database, which contains information on clinical conditions coded in the prior year for
the Centers for Medicare and Medicaid Hierarchical Condition Categories risk adjustment models. The
availability of these two datasets will allow us to examine selection, health care use, quality, and risk coding
though a more refined clinical lens than in our previous P01 research. Our proposal includes three aims. Aim
1 will leverage the newly available MA encounter data to quantify differences in care delivery both between TM
and MA and among MA plans for patients with specific acute and chronic medical conditions. Aim 2 will assess
the potential contributions of various mechanisms to the differences in care identified in Aim 1, focusing first on
network formation and second on examining within- and between-provider differences in care for MA vs. TM
enrollees. We also will be able to examine heterogeneity within the MA program more specifically, as health
plans may adopt different approaches to network formation within an area. Aim 3 will examine the magnitude
of coding intensity differences between MA and TM and among MA plans and explore alternative approaches
to risk adjustment that reduce sensitivity to diagnostic coding practices in performance assessments. By
describing provider networks, examining how networks vary across plans operating in the same market, and
isolating within-provider differences in care for MA and TM enrollees, we will be able to assess the consistency
of various conceptual explanations of care differences between TM and MA with empirical observations now
made possible by the new data sources. This project is a natural extension of our current Program Project. We
build on our prior work by assessing patterns of health care use and outcomes in greater clinical detail and by
exploring potential mechanisms used to achieve those patterns. Understanding the role of private plans in
Medicare is crucial for designing systems of financing and delivery that best serve the elderly and disabled.

## Key facts

- **NIH application ID:** 9937243
- **Project number:** 2P01AG032952-11
- **Recipient organization:** HARVARD MEDICAL SCHOOL
- **Principal Investigator:** Bruce E. Landon
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $330,145
- **Award type:** 2
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9937243

## Citation

> US National Institutes of Health, RePORTER application 9937243, Looking Under the Hood of MA (2P01AG032952-11). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9937243. Licensed CC0.

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