TABLE 7. Median age at earliest known autism spectrum disorder diagnosis among children aged 8 years, by intellectual disability status — Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2020.

Site	Total no. with ASD	All children with an ASD diagnostic statement			Children with an ASD diagnostic statement and IQ score ≤70		Children with an ASD diagnostic statement and IQ score >70		Children with either an ASD diagnostic statement or ASD special education classification
		No. with documented ASD diagnosis	Prevalence of ASD with documented diagnosis	Median age at earliest known diagnosis (mos)	No. with documented ASD diagnosis	Median age at earliest known diagnosis (mos)	No. with documented ASD diagnosis	Median age at earliest known diagnosis (mos)	No. with documented ASD diagnosis or ASD special education classification	Median age at earliest known ASD identification (mos)
Arizona	360	255	19.4	57	66	50.5	139	58	333	60
Arkansas	362	318	20.6	56	144	49.5	147	63	350	58
California	710	560	35.4	36	121	39	384	35.5	673	39
Georgia	553	392	17.9	50	147	48	166	52.5	476	51
Maryland	491	412	19.4	49	127	38.0	138	49	477	53
Minnesota	482	307	19.0	59	105	44	171	65	467	56
Missouri	601	484	19.7	51.5	99	50	194	65	556	56
New Jersey	544	514	27.1	38	131	37	197	39	538	39
Tennessee	713	458	17.9	48	192	36.5	161	56	611	58
Utah	621	471	19.0	56	73	52	168	65	528	58
Wisconsin	808	492	17.1	43	140	35.5	140	50	570	46
Total	6,245	4,663	20.6	49	1,345	43*	2,005	53*	5,579	52

Abbreviation: ASD = autism spectrum disorder.

* Permutation test comparing median age of earliest known diagnosis for children with known IQ score ≤70 versus known IQ score >70 (p<0.001).