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National Ambulatory Medical Care Survey (NAMCS)

National Ambulatory Medical Care Survey (NAMCS)

The National Ambulatory Medical Care Survey (NAMCS) is designed to meet the need for objective, reliable information about the provision and use of ambulatory medical care services in the United States.

Recently, you may have been asked to respond to the National Ambulatory Medical Care Survey (NAMCS). This page provides additional information about the survey, including how to verify the survey is being conducted by the Census Bureau, that the person who contacted you is a Census Bureau employee, what you can expect if you or your facility has been selected to participate in the survey, and how we ensure that the data you provide are protected.

If you have additional concerns that are not addressed on this page, and wish to contact Census Bureau staff regarding the survey, please see the contact information at the bottom of this page.


The National Ambulatory Medical Care Survey (NAMCS) is the Nation’s foremost study of ambulatory care provided at physicians’ offices and has been conducted since 1973. It focuses on visits made to non-federally employed, office-based physicians who are primarily engaged in direct patient care. Since 2006, the survey also includes an annual sample of visits to community health centers (CHCs). From 2012 through 2015, a new sampling design allowed NAMCS to make estimates not only for the nation and four Census regions, but also for up to as many as 34 of the nation’s most populous states. NAMCS provides information on patient, provider, and visit characteristics. It is sponsored by the Centers for Disease Control and Prevention’s (CDCs) National Center for Health Statistics (NCHS), and is administered by the U.S. Census Bureau.

Why is this survey important?

NAMCS participation is important because without your contribution, neither you nor other health care providers like yourself can benefit from being represented in the national description of office-based and CHC-based patient care. You were randomly chosen to represent not only yourself but also thousands of other physicians or advanced practice providers in your geographic region, state, and medical specialty. By participating in NAMCS, you will be able to contribute to the national description of office-based and CHC-based patient care. Your participation will result in more reliable data that will permit researchers, including other health care providers, to better assess the current state of ambulatory medical care utilization and provision. NAMCS fulfills an ongoing need for national statistics on ambulatory care that can be used to improve professional education curricula for health care workers, formulate health policy, inform medical practice management, and evaluate quality of care. Not participating lessens the accuracy of data used by physicians and other researchers.

What is the legal authority for conducting this survey?

NAMCS is authorized by Title 42, United States Code, Section 306 (242k), which permits data collection for health research. The U.S. Census Bureau is conducting this survey on behalf of the National Center for Health Statistics (NCHS) under the authority of Title 13, United States Code (U.S.C.), Section 8(b). We take your privacy very seriously. All information that relates to or describes identifiable characteristics of individuals, a practice, or an establishment will be used only for statistical purposes. NCHS staff, contractors, and agents will not disclose or release responses in identifiable form without the consent of the individual or establishment in accordance with section 308(d) of the Public Health Service Act (42 USC 242m(d)) and the Confidential Information Protection and Statistical Efficiency Act of 2002 (CIPSEA, Title 5 of Public Law 107-347). The Privacy Rule, as mandated by the Health Insurance Portability and Accountability Act (HIPAA), allows private practices and CHCs to participate in NAMCS.

What should you expect if you were randomly selected to be in the survey?

A physician or advanced practice provider selected for NAMCS will first receive a letter from the Director of NCHS describing key points about the survey and letting the physician know that they can expect to be contacted by a representative from the Census Bureau in the near future.

How was I (or my CHC) selected to be in this survey?

Each year, the National Center for Health Statistics (NCHS) scientifically selects a random group of physicians and CHCs throughout the country to participate in NAMCS. This group of physicians is selected from a list of licensed non-federal physicians in office-based practice maintained by the American Medical Association and the American Osteopathic Association. These lists are continually updated by both associations to make them as current and accurate as possible at the time of sample selection. The list of CHCs selected for participation comes from the Health Resources and Services Administration (HRSA). If you are selected, you will receive a letter in the mail from NCHS informing you of that before the Census Bureau contacts you.

How can I verify that I (or my CHC) was selected for this survey?

If you wish to verify that you or your CHC was selected for this survey, you can contact your Census Bureau Regional Office, and they can verify whether you or your CHC were selected for NAMCS (see the map for contact information.)

How can I verify that the person contacting me is a Census Bureau employee?

All Census Bureau field representatives identify themselves by name and carry a badge identifying him/her as a U.S. Census Bureau employee. They will be carrying a laptop with the Census Bureau logo on it to conduct the survey.

If you receive a call or visit and wish to verify that the person contacting you is a Census Bureau employee, you can call one of our regional offices or you can use the staff search on our website.

Is participation mandatory?

Participation in NAMCS is voluntary. However, when you participate, you are representing thousands of other physicians, or advanced practice providers in CHCs in your geographic region, state, and medical specialty. In order to be able to create quality statistics, we rely on the participation of those who are randomly selected. If you choose not to participate, you and others like yourself will not be adequately represented.

Can my patients or I be identified by my responses?

NCHS collects and uses information you provide in accordance with System of Records Notice 09-20-0164, Health and Demographic Surveys Conducted in Probability Samples of the United States. We take your privacy very seriously. We combine your answers with other physician and provider answers in a way that keeps everyone’s identity secret. As required by federal law, your identity can be seen only by those NCHS employees and specially designated agents (such as the U.S. Census Bureau) who need that information for a specific reason. No one else can see your answers until all information that could identify a specific individual has been removed.

Every National Center for Health Statistics (NCHS) employee, contractor, research partner, and agent has taken an oath to keep your information private. Anyone who willfully discloses ANY identifiable information about ANYONE in the survey could get a jail term of up to five years, a fine of up to $250,000, or both. Per the Federal Cybersecurity Enhancement Act of 2015 (6 U.S.C. §§ 151 & 151 note), your data are protected from cybersecurity risks through screening of the systems that transmit your data.

How do I know my responses are safe?

The responses that are collected from surveys conducted by the Census Bureau are encrypted both in transit and at rest on the Census Bureau’s computer servers. These servers are part of a stand-alone network that is not accessible by the Internet. In addition, these servers are constantly monitored for any signs of intrusions.

Where can I find the statistics produced by this survey?

To see examples of reports, tables, and charts that use data from the survey, you can visit NCHS’s website on Ambulatory Medical Care Data.

What if I have additional questions, recommendations, or issues that I need resolved?

If you have additional questions about the survey, or if you wish to speak to someone at the Census Bureau, you can contact the respondent advocate. The respondent advocate can address the concerns of those hospitals that have been selected to participate in this survey, as well as share that feedback with those who manage the survey operations.

The Census Bureau has a web page “Are You In A Survey” designed to answer additional questions you might have about being in a Census survey.

For more Frequently Asked Questions about NAMCS, please see:

Page Last Revised - October 28, 2021
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