Ambulatory Health Care Data

Welcome NAMCS Participants

The National Health Care Surveys (including NAMCS, NHAMCS, and NHCS) are working with the Centers for Medicare and Medicaid Services Electronic Health Record Incentive Programs: Promoting Interoperability (PI) (formerly known as Meaningful Use, or MU) and the Merit-based Incentive Payment System (MIPS). Click here to find out more.


Contact Information

If you have any questions or comments related to participation, please contact the Ambulatory Care Team at:

Ambulatory and Hospital Care Statistics Branch
National Center for Health Statistics
3311 Toledo Road
Hyattsville, Maryland 20782
Phone: 800-392-2862
Fax: 301-458-4032

If you have questions about the survey that are not related to participation, please contact:

Ambulatory and Hospital Care Statistics Branch
National Center for Health Statistics
3311 Toledo Road
Hyattsville, Maryland 20782

Contact CDC-INFO


What is NAMCS?

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. From 2012 through 2015, a new sampling design allowed NAMCS to make estimates for the nation, nine U.S. Census divisions, four U.S. Census regions, and depending on the year, a select number of individual US states. NAMCS provides information on patient, provider, and visit characteristics. There is also a Health Center Component of NAMCS. From 2006 through 2020, NAMCS included an annual sample of visits to Community Health Centers. In 2021, the Health Center Component was redesigned to begin collecting data using electronic health records. More information on the Health Center Component can be found here.

The annual NAMCS physician sample is composed of doctors of medicine (MDs) and doctors of osteopathy (DOs), representing an array of medical specialties.  Physicians are randomly selected based on information obtained from the master files of the American Medical Association (AMA) and the American Osteopathic Association (AOA).

These data are widely used by health care researchers, medical schools, policy analysts, congressional staff, the news media, and many others to improve our knowledge of medical practice patterns.

Reliable NAMCS data depend on complete reports from all sampled providers.  Data are needed to ensure that policy decisions are based on the most accurate information possible.


Your participation is vital to the success of the survey

NAMCS Graphic - Your participation is important


NAMCS Participation

  • Who is eligible to participate?
    Non-federally employed physicians (excluding those in the specialties of radiology and pathology) who are classified by the AMA or the AOA as primarily engaged in office-based patient care are randomly chosen to participate in NAMCS. Participation in NAMCS is completely voluntary.
  • Why participate?
    NAMCS participation is important because without your contribution, neither you nor other health care providers like you can benefit from being represented in the national description of office-based patient care. You were randomly chosen to represent not only yourself, but also thousands of other physicians in your geographic region, state, and medical specialty.
  • What are the benefits of participating?
    By participating in NAMCS, you will be able to contribute to the national description of office-based patient care. Participation will result in more reliable data which 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. Failure to participate lessens the accuracy of data used by physicians and other researchers.
  • How does the process work?
    A stratified, random sample of physicians is selected. . Letters informing physicians about the purpose of the study are sent first. Then, within two weeks of the physician’s earliest induction date, the physician is typically contacted by a U.S. Census Bureau field representative (FR) who confirms that the physician is eligible for participation. Once confirmed as eligible, the FR will conduct an induction interview (usually in-person) with the physician.
  • How are NAMCS data used?
    NAMCS data are currently used to provide statistics that describe the characteristics of visits to physician offices. The data elements include patient demographic characteristics; the conditions most often treated; and the diagnostic and therapeutic services rendered, including medications prescribed. These data are used by the U.S. Congress and other public health policy makers, government agencies, universities and medical schools, professional associations, health services researchers and epidemiologists, as well as the print, broadcast, and web media to describe and understand the changes that occur in medical practice. The data are disseminated in the form of government reports, journal articles, and microdata files.

For information on the confidentiality of NAMCS data, please go to the Privacy Protection page and Frequently Asked Questions (FAQ’s) about NAMCS. If you would like more information on participation, please contact or (800)392-2862.


NAMCS Survey Results and Products

NCHS publishes a number of web tables, reports, and factsheets using NAMCS data. A list of all these available products can be found here.

Professional Endorsements

A number of professional organizations have formally endorsed NAMCS, including:

  • American Academy of Ambulatory Care Nursing
  • American Academy of Dermatology
  • American Academy of Family Physicians
  • American Academy of Neurology
  • American Academy of Ophthalmology
  • American Academy of Pediatrics
  • American Academy of Physical Medicine and Rehabilitation
  • American College of Cardiology
  • American College of Obstetricians and Gynecologists
  • American College of Physicians
  • American College of Preventive Medicine
  • American College of Surgeons
  • American Osteopathic Association
  • American Psychiatric Association
  • American Society of Clinical Oncology
  • American Society of Plastic Surgeons
  • American Urological Association


NAMCS Data Supplements and Initiatives

Current Data Supplements and Initiatives

The 2021 NAMCS continues to include data collection on certain items of special interest to health policy researchers:

  • Physician Workforce
    The physician workforce question set, sponsored by the Office of the Assistant Secretary for Planning and Evaluation (ASPE), was first added to the National Ambulatory Medical Care Survey Physician Induction Interview in 2013 and has been continued every year since. These questions provide a description of the composition of the practice team and the roles/responsibilities of its respective members.
  • Physician Experiences Related to COVID-19
    The COVID-19 question set was added period 3 of the 2020 National Ambulatory Medical Care Survey Physician Induction Interview to evaluate physicians’ pandemic related experiences. Question topics were personal protective equipment shortages; COVID-19 testing experiences; providers in their office who tested positive for COVID-19; turning away COVID-19 patients; and telemedicine or telehealth technology use at their office. For more information, please see the “Physician Experiences Related to COVID-19” component of the NCHS COVID-19 Dashboard.
Page last reviewed: December 30, 2021