Medically Underserved Areas and Populations (MUA/Ps)

Medically Underserved Areas (MUAs) and Medically Underserved Populations (MUPs) identify geographic areas and populations with a lack of access to primary care services.

MUAs have a shortage of primary care health services for residents within a geographic area such as:

  • a whole county; 
  • a group of neighboring counties; 
  • a group of urban census tracts; or 
  • a group of county or civil divisions.

MUPs are specific sub-groups of people living in a defined geographic area with a shortage of primary care health services.  

These groups may face economic, cultural, or linguistic barriers to health care.


  • Homeless
  • Low-income
  • Medicaid-eligible
  • Native American
  • Migrant farmworkers

MUA/P designations are based on the Index of Medical Underservice (IMU).  The IMU is calculated based on four criteria:

  • the population to provider ratio;
  • the percent of the population below the federal poverty level;
  • the percent of the population over age 65; and
  • the infant mortality rate.  

IMU can range from 0 to 100, where zero represents the completely underserved.  Areas or populations with IMUs of 62.0 or less qualify for designation as an MUA/P.  

Exceptional MUP Designations

It is possible to request a MUP designation for populations which do not meet the established criteria.

You must do the following:

  • Explain the unusual, documented local conditions that prevent access to, or demonstrate the lack of, personal health services, and
  • Submit a written recommendation, with supporting data, from that state’s governor or other Chief Executive Officer, and the local health official. 

Find out more about the MUA/P designation process.

Date Last Reviewed:  June 2019