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Coronavirus Relief Fund 

Frequently Asked Questions on Tribal Population

June 4, 2020

Why did Treasury allocate funding based on Tribal population using the Decennial Census 

total American Indian Alaskan Native (AIAN) data used by the Department of Housing 

and Urban Development (HUD) in its Indian Housing Block Grant Program (IHBG)?

Treasury used the Decennial Census data on AIAN population that is used in the IHBG program

after making the determination that it is the most consistent and reliable metric on which to base 

the allocation of payments to Tribal governments. The methodology for calculating population 

for the IHBG formula was developed through negotiated rulemaking with tribes in the mid1990s and has been reconsidered over the years, including a negotiated rulemaking session that 

concluded in 2016. Using these data, which are updated annually using the Census Bureau’s 

Population Estimates Program (PEP) to reflect demographic shifts that have occurred at the 

county level, provides consistency between Tribal governments and states and local 

governments. Treasury used PEP data to allocate funding to the state and local governments 

under the CARES Act. Tribal governments are familiar with these data, and have had the 

opportunity to challenge them in the past. Finally, the data has been used in other funding 

formulas that disburse payments to tribes.

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What population data did Treasury use for Indian Tribes not included in the IHBG 

population data?

Treasury requested population data from HUD for the three federally-recognized Indian Tribes

that are not included in the IHBG population data. Those Indian Tribes are: Mohegan Tribe of 

Indians of Connecticut, Prairie Island Indian Community, and Chicken Ranch Rancheria of MeWuk Indians.

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Although they do not participate in the IHBG program, these tribes do have Decennial Census 

data attributed to their defined formula areas under the IHBG program. HUD provided the 

following population figures for each of the tribes by applying the PEP adjustments in the same

manner as is done for tribes that do participate in the IHBG program.

Tribe Single Race Multi Race

Chicken Ranch 1 1

Mohegan 28 32

Prairie Island 195 219

Treasury used this data in the allocation methodology. 

 

1 For example, the funding formula under the Tribal Transportation Program, established to address the 

transportation needs of Tribal governments throughout the United States, is calculated, in part, using the same 

Decennial Census AIAN population used in the IHBG program. See 23 U.S.C. 202(b)(3)(B). 

2 These tribes formally withdrew from the IHBG program and asked HUD not to be included in the IHBG formula 

allocation.
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Why did Treasury not use the tribal enrollment data as a proxy for population data?

Tribal enrollment does not provide a consistent measure of tribal population across tribes. Tribal 

enrollment criteria are set forth in tribal constitutions, articles of incorporation, or ordinances, 

and vary from tribe to tribe.3 Additionally, tribal enrollment data does not necessarily 

distinguish between members living within the tribal area from those living outside the tribal 

area. Instead, “formula areas”, as incorporated in the IHBG population data, correspond broadly 

with the area of a Tribal government’s jurisdiction, where it provides services, and include

adjustments to address overlapping jurisdictions.

Our tribe’s enrollment data is substantially larger than the Decennial Census AIAN 

population data. Can you explain the difference?

The IHBG program population count is tied to each tribe’s formula area – a specific geographic 

area attributed to each tribe. Because tribal enrollment does not necessarily distinguish between 

those living inside and outside of the tribal area, tribal enrollment can significantly differ from 

the Decennial Census AIAN population data used in the IHBG program. 

Why did Treasury not use the population estimates from the American Community Survey 

(ACS) data?

Treasury did not use ACS population data because the ACS sampling and weighting is based at 

the county level and since tribal areas are sub-county entities, the tribal population can fluctuate

substantially from year-to-year.

 

3 https://www.doi.gov/tribes/enrollment.