physician_shared_patients — Medicare physician shared patient patterns (2009-2015)

Description

Networks of health care providers (physicians, other practitioners and organizations such as hospitals, laboratories and home health agencies) of the US Medicare program that took part in the care of the same patients, released by the Centers for Medicare & Medicaid Services (CMS) in response to a Freedom of Information Act request (the data are also known as "DocGraph", after the project that requested them). They were computed by CMS from the Medicare fee-for-service claims (and the Medicare Advantage encounter claims) of each calendar year, from 2009 to 2015.

Each node is a provider, identified by its National Provider Identifier (NPI), and a directed edge from provider A to provider B means that, for some beneficiaries, a claim of B followed a claim of A within a given time window (30, 60, 90 or 180 days) after it. A provider is counted when it appears on a claim in any role of "treatment association" (billing organization, attending, operating, rendering or ordering physician, ...), except as referring physician or as supplier of durable medical equipment. Relationships from claims of the same day are assigned to the lesser of the two NPIs (as source). The identifiers are as given by CMS: a few thousand edges (e.g. 4,410 in 2009_days30) involve identifiers that are not valid NPIs (with a leading zero), which are kept as they are. Pairs of providers that shared fewer than 11 distinct beneficiaries in the year were left out by CMS, to protect the privacy of the patients, so that the networks are thresholded at this value (the unthresholded data are not public). Since the windows extend beyond the end of the year, the claims considered for a year run until one, two, three or six months into the next one; the data of 2015 only cover claims until September or October 2015 (shorter windows than the others for the 60, 90 and 180 day periods).

There is one network for each year and time window, named <year>_days<window> (e.g. 2014_days30, 2014_days180); the networks of longer windows contain those of shorter windows of the same year.

The metadata of the providers (name, type, specialty, location) are taken from the National Plan and Provider Enumeration System (NPPES), the registry of the NPIs, in its monthly file of October 2026 (data until 11 October 2026, from the mirror of the National Bureau of Economic Research): they are therefore those of the download date, not of the years of the networks (providers move, change names and specialties), and they are missing for the identifiers that are not in the NPPES (invalid identifiers), and empty for the deactivated NPIs (whose data the NPPES does not disclose). The specialty is given by the primary taxonomy code of the provider, described by the Health Care Provider Taxonomy code set of the National Uniform Claim Committee (NUCC, version 26.1).

The networks have the following properties:

(Node) npi: the National Provider Identifier of the provider, as given (a ten-digit number; a few identifiers are invalid, e.g. D038101571).
(Node) in_nppes: whether the NPI is in the NPPES file of October 2026.
(Node) entity_type: individual or organization (empty if not in the NPPES or deactivated).
(Node) name: the name of the provider (first, middle and last name for individuals, the legal business name for organizations).
(Node) credential (individuals): the credentials, as given (e.g. M.D.).
(Node) taxonomy_code: the primary Health Care Provider Taxonomy code (e.g. 207R00000X; the first one if none is marked as primary).
(Node) specialty: its description (classification and specialization, e.g. Internal Medicine, Internal Medicine, Cardiovascular Disease).
(Node) city, state, zip5: the location of the practice (city, two-letter state code, and the first five digits of the ZIP code; the state may also be a foreign one, with the country in country).
(Node) country: the country code of the practice location (US for the United States).
(Edge) pairs: the number of times a claim of the target followed a claim of the source within the window (the "pair count").
(Edge) beneficiaries: the number of distinct beneficiaries shared by the two providers (at least 11).
(Edge) same_day: the number of these sharing events in which both claims were on the same day.
(Node) start (graph), end (graph): the date range of the claims considered, as given by CMS (e.g. 2009-01-01 and 2010-02-01 for 2009_days30).

Tags

Social Public Health Offline Weighted Metadata

Added

2026-10-28

Citation

Centers for Medicare & Medicaid Services, "Physician Shared Patient Patterns." Technical requirements (2015) downloads.cms.gov
Centers for Medicare & Medicaid Services, "National Plan and Provider Enumeration System (NPPES) Downloadable File." October 2026, mirrored by the National Bureau of Economic Research www.nber.org
National Uniform Claim Committee, "Health Care Provider Taxonomy Code Set." Version 26.1 (2026) www.nucc.org

Upstream URL OK

https://www.cms.gov/Regulations-and-Guidance/Legislation/FOIA/Referral-Data-FAQs
https://downloads.cms.gov/foia/physician_shared_patient_patterns_technical_requirements.pdf
https://www.nber.org/research/data/national-plan-and-provider-enumeration-system-nppesnpi
https://www.nucc.org/index.php/code-sets-mainmenu-41/provider-taxonomy-mainmenu-40/csv-mainmenu-57

Upstream license

Public domain (US government work), https://www.usa.gov/government-copyright

Networks

Tip: click on a column header to sort the list, or hover over it for a description.

Column legend

$\left<k\right>$: Mean degree
$\sigma_k$: Standard deviation of the degrees
$\lambda_h$: Largest eigenvalue of the Hashimoto (non-backtracking) matrix
$\tau$: Random walk mixing time
$r$: Degree assortativity
$c$: Global clustering coefficient
$\oslash$: (Pseudo-) diameter
$S$: Relative size of the largest component
NPs: Node properties
EPs: Edge properties

Name	Nodes	Edges	$\left<k\right>$	$\sigma_k$	$\lambda_h$	$\tau$	$r$	$c$	$\oslash$	$S$	Kind	Mode	NPs	EPs	gt	GraphML	GML	csv
2009_days30	890,452	50,382,951	56.58	478.84	529.63	152.94	-0.03	0.08	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	221.0 MiB	433.2 MiB	445.6 MiB	390.2 MiB
2009_days60	914,428	67,915,893	74.27	598.72	651.52	94.70	-0.02	0.08	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	292.6 MiB	576.0 MiB	600.4 MiB	515.6 MiB
2009_days90	931,354	82,635,748	88.73	687.26	747.69	91.11	-0.02	0.08	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	353.6 MiB	695.9 MiB	730.2 MiB	620.7 MiB
2009_days180	965,571	119,270,681	123.52	886.53	978.56	96.44	-0.02	0.09	8	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	507.4 MiB	995.3 MiB	1.027 GiB	N/A
2010_days30	921,959	52,236,906	56.66	490.38	547.09	151.72	-0.03	0.07	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	229.4 MiB	N/A	N/A	N/A
2010_days60	949,164	70,640,468	74.42	616.90	676.24	101.87	-0.03	0.08	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	305.6 MiB	N/A	N/A	N/A
2010_days90	968,082	86,116,496	88.96	711.73	779.02	95.24	-0.02	0.08	9	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	368.7 MiB	N/A	N/A	N/A
2010_days180	1,005,343	124,844,963	124.18	931.02	1030.23	104.26	-0.02	0.09	9	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	531.4 MiB	N/A	N/A	N/A
2011_days30	955,659	54,038,549	56.55	494.39	555.36	131.57	-0.03	0.07	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	238.0 MiB	N/A	N/A	N/A
2011_days60	985,066	73,545,008	74.66	637.73	703.09	121.30	-0.02	0.07	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	318.5 MiB	N/A	N/A	N/A
2011_days90	1,003,988	89,506,481	89.15	742.90	815.49	120.26	-0.02	0.08	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	384.3 MiB	N/A	N/A	N/A
2011_days180	1,041,734	129,968,445	124.76	980.03	1080.09	118.09	-0.02	0.08	9	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	555.6 MiB	N/A	N/A	N/A
2012_days30	987,770	54,966,715	55.65	506.95	568.42	111.30	-0.03	0.07	13	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	242.7 MiB	N/A	N/A	N/A
2012_days60	1,017,878	74,795,384	73.48	650.74	718.21	100.94	-0.02	0.07	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	324.5 MiB	N/A	N/A	N/A
2012_days90	1,037,302	91,175,470	87.90	755.90	831.22	100.72	-0.02	0.07	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	392.4 MiB	N/A	N/A	N/A
2012_days180	1,076,910	133,042,645	123.54	993.70	1098.45	102.95	-0.02	0.08	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	567.5 MiB	N/A	N/A	N/A
2013_days30	1,018,245	55,141,669	54.15	520.84	578.91	228.70	-0.02	0.06	13	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	244.8 MiB	N/A	N/A	N/A
2013_days60	1,048,383	75,144,583	71.68	668.63	727.53	104.98	-0.02	0.06	12	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	326.9 MiB	N/A	N/A	N/A
2013_days90	1,068,349	92,004,979	86.12	776.92	840.92	105.66	-0.02	0.07	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	397.1 MiB	N/A	N/A	N/A
2013_days180	1,108,696	135,071,996	121.83	1014.25	1105.85	104.47	-0.02	0.07	9	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	578.6 MiB	N/A	N/A	N/A
2014_days30	1,044,758	55,779,360	53.39	523.79	586.85	104.07	-0.02	0.06	13	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	247.6 MiB	N/A	N/A	N/A
2014_days60	1,076,243	76,415,894	71.00	674.26	738.78	96.93	-0.02	0.06	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	333.0 MiB	N/A	N/A	N/A
2014_days90	1,097,652	94,074,258	85.70	785.73	855.83	92.19	-0.02	0.06	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	406.4 MiB	N/A	N/A	N/A
2014_days180	1,138,835	138,614,191	121.72	1029.77	1125.33	87.16	-0.02	0.07	10	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	594.3 MiB	N/A	N/A	N/A
2015_days30	961,309	34,856,901	36.26	395.42	443.67	107.47	-0.03	0.05	12	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	159.1 MiB	N/A	N/A	N/A
2015_days60	1,009,934	49,335,361	48.85	519.69	566.21	107.27	-0.03	0.05	12	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	218.5 MiB	N/A	N/A	N/A
2015_days90	1,020,793	56,040,265	54.90	576.97	623.90	154.01	-0.03	0.05	13	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	246.0 MiB	N/A	N/A	N/A
2015_days180	1,034,612	65,739,582	63.54	651.21	706.63	87.36	-0.03	0.05	11	1.00	Directed	Unipartite	npi in_nppes entity_type name credential taxonomy_code specialty city state zip5 country	pairs beneficiaries same_day	285.3 MiB	N/A	N/A	N/A