Health insurance programs supported by federal and state tax dollars are a critical source of health insurance coverage for children in the United States. The National Health Interview Survey (2022) estimated that 43.7% of children under the age of 18 in the U.S. had publicly supported health insurance coverage. This includes child coverage through Medicaid, the Children's Health Insurance Program (CHIP), Medicare, state-sponsored or other government-sponsored health plans, and military plans.  The critical drivers of public health insurance coverage for children in the U.S. are Medicaid and CHIP.  Medicaid is the joint state-federal health insurance program for eligible individuals with limited income and resources, while CHIP is a joint state-federal effort to make available health insurance for children from families with low incomes, but incomes not low enough to qualify for Medicaid coverage.  As of January 2023, federal reports indicate that there were about 41.9 million children enrolled in Medicaid or separate CHIP programs.

That same January 2023 data reveals that the four-state Southwestern U.S., excluding Arizona, had over 5.3 million children enrolled in either Medicaid or separate CHIP programs.  Of the total January 2023 Medicaid child and CHIP enrollment reported by 49 states and the District of Columbia, the Southwestern U.S. accounted for about 12.7% of the national total.  Here is a summary look at Medicaid child and CHIP enrollment in the Southwestern U.S. as of January 2023:

Medicaid Child and CHIP Enrollment in the Southwestern U.S.

Area Name	Enrollment	% of U.S. Total
Arizona	N/A	N/A
New Mexico	383,708	0.9%
Oklahoma	646,255	1.5%
Texas	4,303,448	10.3%
Region	5,333,411	12.7%
United States (1)	41,859,753	100.0%

(1) National figures are for the 49 states and the District of Columbia that reported child enrollment data for January 2023

Source: Medicaid.gov Enrollment Reports as of January 2023