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.

State Primary Care Offices (PCOs) use the Shortage Designation Management System (SDMS) to submit MUA and MUP applications to HRSA for review.*

Medically Underserved Areas (MUAs)

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 census tracts; or 
  • a group of county or civil divisions.

Medically Underserved Populations (MUPs)

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


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

Eligibility for MUP

Eligibility for MUP designation depends on the Index of Medical Underservice (IMU) calculated for the area or population proposed for designation. Under the established criteria, an area or population with an IMU of 62.0 or below qualifies for designation as an MUA/P.

How the Index of Medical Underservice (IMU) works

The IMU scale is from zero to 100. Zero represents completely underserved. One hundred represents least underserved. 

HRSA calculates the IMU by assigning a weighted value to an area or population’s performance on four demographic and health indicators. The weighted values are then added together.

Demographic and Health Indicators

  • Provider per 1,000 population ratio
  • % Population at 100% of the Federal Poverty Level (FPL)
  • % Population age 65 and over
  •  Infant Mortality Rate

Provider per 1,000 population ratio (28.7 points max) plus percent of population at 100% FPL (25.1 points max) plus percent population age 65 and over (20.2 points max) plus infant mortality rate (26 points max) equals IMU Score (out of 100)

Exceptional MUP Designations

Governors may designate population groups within a geographic area of their state as shortage areas using a state-created and HRSA-certified Shortage Area Plan. The State Shortage Area Plan must outline how to identify populations that need services, but do not otherwise qualify for MUA/P designation.

States wishing to acquire a Governor’s Exceptional MUP Shortage Area must submit:

  • A signed letter from the governor explaining the unusual, documented local conditions that prevent access to, or demonstrate the lack of primary care health services; and,
  • A state-specific Shortage Area Plan detailing, at minimum state’s rational service area criteria and component guidelines for HRSA’s approval.

The Exceptional MUA/P applications are submitted to HRSA via mail.

Date Last Reviewed:  May 2020