Table 1. Census Tracts and Block Groups Assigned to Multiple TRRs by Absolute Area and Percentage Area.

Method	Spatial unit	No. double-assigned	Area double-assigned, km2 (%)
Spatial	Block group	0	0
	Census tract	0	0
Zip	Block group	7657	1 641 994 (18.0)
	Census tract	2449	1 641 999 (18.0)

Abbreviation: TRRs, transplant referral regions.