CMS Data Research Dataset

About the Dataset

CMS publishes Medicare Advantage and Part D enrollment, plan, and service-area data every month, spread across dozens of separate file releases dating back to 2001. The CMS Data Research Dataset turns that into one queryable database: every feed loaded as a typed, aligned SQL view, refreshed automatically as CMS publishes, with monthly history preserved for trend analysis.

16+ research feeds cover Medicare Advantage and Part D enrollment by contract, plan, state, and county; plan crosswalks; Special Needs Plan reports; and service areas — 2,500+ files, over two decades of history. Every view aligns and casts the source attributes so queries stay stable across releases.

Need a research feed that isn't in the catalog yet? We can add it on demand — reach out and we'll evaluate it.

Get Full Access | Snowflake Marketplace | Databricks | Databricks Marketplace | Free Trial

What You Get

16+ research feeds, history since 2001	Medicare Advantage & Part D enrollment by contract, plan, state, and county; plan crosswalks; SNP reports; service areas
Automatic file updates	New feed files load automatically as CMS publishes each monthly release
Aligned, typed SQL views	Every feed's file attributes cast and aligned to a stable schema, so queries don't break across releases
History preserved	Monthly releases retained back to 2001 for longitudinal enrollment and plan-level trend analysis
Available on Snowflake & Databricks	Query as typed SQL views on Snowflake Marketplace, or as Delta Sharing tables on Databricks
Coverage	2,500+ files across 16+ feeds, checked daily as CMS releases new data

See the full list of feeds included in the CMS Data Research Catalog.

What Is CMS Data? Research Feeds vs Public Datasets

CMS data is the information published by the Centers for Medicare & Medicaid Services (CMS) about Medicare and Medicaid — enrollment, plans, providers, spending, and quality. It comes in two broad forms, and this product covers one of them: the CMS data-research feeds from cms.gov's data-research area — Medicare Advantage and Part D enrollment counts, plan crosswalks, service areas, and county penetration — delivered as queryable SQL views with history back to 2001.

For the broader catalog of public CMS datasets published on catalog.data.gov and data.cms.gov, see the companion CMS Data Feeds Dataset. Many teams use both together: the research feeds for Medicare enrollment and plan analysis, the public feeds for everything else CMS publishes.

The CMS Research Datasets, in One Queryable Database

Instead of downloading CMS enrollment and plan files one monthly release at a time, you get every CMS data-research feed as a typed SQL view in one database — Medicare Advantage and Part D enrollment by contract, plan, state, and county; plan crosswalks; SNP reports; and service areas. The dataset spans 16+ feeds and 2,500+ files, with monthly releases back to 2001 preserved for trend analysis. Every view aligns and casts the source attributes so queries stay stable across releases.

Data Quality and Maintenance

At Dataplex Consulting & Data Products, we prioritize data quality:

• Daily monitoring of ingestion and ETL jobs

• Automated data quality checks to prevent bad data from reaching customers

• Timely updates when CMS publishes new information

• Consistent data structure across feeds for ease of use

Business Applications

The CMS Data Research Dataset can be utilized for various purposes, including:

• Enriching or augmenting existing datasets

• Analyzing published feed metrics over time

• Performing segmentation analysis

• Training machine learning models

• Conducting geospatial analysis

Example Use Cases

1. Analyzing enrollment counts by plan

2. Tracking eligible and enrolled individuals in Part-D Plans by location

3. Monitoring Special Needs Dual-Eligible Enrollment Counts over time

4. Examining enrollment metrics by state

5. Accessing the most recent plan crosswalk data

Data Structure

The dataset includes 16 feeds as of December 2023:

1. 2015 Part C&D Plan Crosswalk

2. Enrollment by Contract

3. MA Contract Service Area

4. MA Enrollment by SCC

5. MA Enrollment by SCP

6. MA State/County Penetration

7. Monthly Enrollment by CPSC

8. Monthly Enrollment by Plan

9. Monthly Enrollment by State

10. PBP Benefits 2017

11. PDP Contract Service Area

12. PDP Enrollment by SCC

13. PDP Enrollment by SCP

14. PDP State/County Penetration

15. SNP Comprehensive Report

16. State Service Area

Entity Relationship Diagram

CMS Data Research Schema

Sample Queries

Query the Enrollment Count by Plan as of October 2019

Snowflake

select s.organization_type,
       s.plan_id,
       s.plan_type,
       s.organization_name,
       s.enrollment
from dwv.feeds f
join dwv.feeds_files ff
  on f.id = ff.feed_id
join dwv.MONTHLY_ENROLLMENT_BY_PLAN s
  on ff.id = s.file_id
 and f.id = s.file_feed_id
 and ff.file_report_period = to_date('2019-10-01','YYYY-MM-DD')
order by s.enrollment desc nulls last;

Databricks

select s.organization_type,
       s.plan_id,
       s.plan_type,
       s.organization_name,
       s.enrollment
from cms_research_dwv.feeds f
join cms_research_dwv.feeds_files ff
  on f.id = ff.feed_id
join cms_research_dwv.monthly_enrollment_by_plan s
  on ff.id = s.file_id
 and f.id = s.file_feed_id
 and ff.file_report_period = to_date('2019-10-01','YYYY-MM-DD')
order by s.enrollment desc nulls last;

Query the Eligible and Enrolled in Part-D Plans in West Baton Rouge by Month

Snowflake

select ff.file_report_period,
       s.eligibles,
       enrolled,
       penetration
from dwv.feeds f
join dwv.feeds_files ff
  on f.id = ff.feed_id
join dwv.PDP_STATE_COUNTY_PENETRATION s
  on ff.id = s.file_id
 and f.id = s.file_feed_id
 and state_name = 'Louisiana'
 and county_name = 'West Baton Rouge'
order by file_report_period;

Databricks

select ff.file_report_period,
       s.eligibles,
       enrolled,
       penetration
from cms_research_dwv.feeds f
join cms_research_dwv.feeds_files ff
  on f.id = ff.feed_id
join cms_research_dwv.pdp_state_county_penetration s
  on ff.id = s.file_id
 and f.id = s.file_feed_id
 and state_name = 'Louisiana'
 and county_name = 'West Baton Rouge'
order by file_report_period;

Frequently Asked Questions

What is CMS data? CMS data is the information published by the Centers for Medicare & Medicaid Services (CMS) about Medicare and Medicaid — including enrollment, plan, provider, spending, and quality data. This product delivers the CMS data-research feeds (Medicare Advantage and Part D enrollment and plan data) as ready-to-query SQL views.

How is this different from the CMS Data Feeds Dataset? This dataset focuses on the CMS data-research feeds — Medicare Advantage and Part D enrollment, plan crosswalks, and county penetration from cms.gov's data-research area, with history back to 2001. The broader CMS Data Feeds Dataset covers the full catalog of public CMS datasets on catalog.data.gov and data.cms.gov. Many customers subscribe to both.

How do I access the CMS research data? It's available on the Snowflake Marketplace as typed SQL views, with a 14-day free trial that includes the first 1,500 rows of every feed file table.

How far back does the data go? The CMS data-research feeds are included back to 2001, with monthly releases preserved so you can trend enrollment and plan metrics over time.

Support and Contact

For any questions or assistance with the CMS Data Research Dataset:

• Email: [e-mail]

• Daily monitoring and support provided by the Dataplex Consulting & Data Products team

About Dataplex

Dataplex Consulting & Data Products delivers turnkey, analytics-ready data products that make complex public and commercial data easy to use across modern data platforms. Our data pipelines include automated quality checks and active monitoring to ensure timely, reliable, and well-structured data that is ready for downstream analytics, machine learning, and operational use.

In addition to data products, Dataplex provides data engineering and analytics consulting services to organizations of all sizes. We bring deep, hands-on experience supporting both early-stage companies and large enterprises, helping teams build scalable data platforms, improve data reliability, and become more data-driven.