Chapter 1.2 · The first year

Infant mortality

Infant mortality in 2018 to 2022 ran from 3.7 per 1,000 in Massachusetts and New Hampshire to 8.7 in Mississippi, and across large counties it rises from 3.9 in the least deprived quarter to 7.2 in the most deprived, with Black mothers' infants dying at 2.2 times the rate of white mothers' in 2018 and 2019.

Author: Vishal Singh
Affiliation: NYU Stern
Published: 9 October 2026

The United States recorded 102,503 infant deaths among 18.5 million live births in 2018 to 2022, a rate of 5.5 deaths per 1,000. The rate was 8.7 in Mississippi and 3.7 in Massachusetts and New Hampshire. Among the 240 large counties that publish a death count in every year, it rises from 3.9 in the least deprived quarter of counties to 7.2 in the most deprived. In 2018 and 2019, the only years for which the linked birth and infant death file reports the mother's race, the rate was 10.3 for infants of Black mothers and 4.7 for infants of white mothers.

These are rates for states, counties and groups of births. They describe where and among whom infants died and say nothing about why a particular infant did. The conditions that come before many infant deaths, low birthweight and preterm birth, are in Chapter 1.1, Birthweight and preterm birth, which also shows infant mortality for Black and white mothers by county deprivation. The fall in the number of births is in Chapter 1.3, Where births are falling.

What the rate counts and where the numbers come from

An infant death is the death of a baby before its first birthday. The infant mortality rate divides such deaths by live births and is reported here as deaths per 1,000. It is a crude rate, with no adjustment for the age or health of mothers. Researchers also split infant deaths by age. Neonatal deaths occur before 28 days of age, and postneonatal deaths occur from that age to the first birthday. A comparison of the United States with European countries found that the American disadvantage is concentrated in the postneonatal period and among infants of lower socioeconomic status.[1]

The numbers come from the linked birth and infant death records on CDC WONDER, which match each infant death certificate to the infant's birth certificate.[2] State files cover all 51 jurisdictions, and WONDER publishes every state total in full. County files name only counties of 250,000 residents or more, pool every other county in a state into one row, and withhold any county cell with fewer than 10 deaths. A withheld cell is missing, not zero, and nothing in this chapter is derived from a total minus the cells that are published. The state file for 2021 gives a national rate of 5.44, which is the rate NCHS reports for that year.[2]

WONDER weights infant deaths in the linked file, so a count can differ from the number of death records, and the age groups from a total, by rounding.

State rates vary widely and most of the highest are in the South

Mississippi has the highest state rate, 8.7 (95% CI 8.3 to 9.2). Massachusetts, at 3.7 (95% CI 3.5 to 3.9), and New Hampshire, at 3.7 (95% CI 3.2 to 4.2), have the lowest rates, and their intervals overlap. The ratio of the rate in Mississippi to the rate in Massachusetts is 2.4 (95% CI 2.2 to 2.6) (Figure 1). Arkansas, Louisiana and Alabama follow Mississippi. The Census South region holds 7 of the 10 states with the highest rates and 17 of the 51 jurisdictions, and the remaining states in that group are Ohio, South Dakota and Indiana. Pooled over births, the rate in the South is 6.3 (95% CI 5.9 to 6.9) against 5.1 (95% CI 4.6 to 5.7) in the rest of the country, a ratio of 1.2 (95% CI 1.1 to 1.4). Within the rest, the Midwest has 6.1 (95% CI 5.5 to 6.5), close to the South, while the Northeast has 4.5 (95% CI 3.9 to 5.2) and the West 4.6 (95% CI 4.3 to 5.3). Intervals resample whole states.

Of the 51 jurisdictions, 21 have an interval entirely above the national rate and 16 have one entirely below it. The others cannot be told apart from the national rate on these counts. The pooled period includes the pandemic years, but no single year sets the pooled rates: the national rate was lowest in 2020, at 5.4, and highest in 2018, at 5.7.

Figure 1

Infant mortality ran from 3.7 per 1,000 in Massachusetts and New Hampshire to 8.7 in Mississippi

Infant deaths per 1,000, by state and DC, 2018 to 2022; the first tab maps the rates and the second ranks them with intervals

7 of the 10 states with the highest infant mortality rates are in the South, which has 6.3 deaths per 1,000 against 5.1 elsewhere

Infant deaths per 1,000 live births, 2018 to 2022

Fewer infant deathsMore infant deaths

Values outside 3 to 9 take the end colors.

No data (0 states)

Select a class to show only those places.

Find a state

Hover or tap a state for its value, or search by name.

Tiles toward the high end of the key are states with more infant deaths per birth; each tile prints its rate, and hovering gives the interval and the births behind it.

Show data

Data for Infant mortality ran from 3.7 per 1,000 in Massachusetts and New Hampshire to 8.7 in Mississippi, Map of states
conf_high	conf_low	n	rate	state
6.74	5.35	48,103	6.05	AK
7.49	6.87	290,226	7.18	AL
8.03	7.22	180,269	7.63	AR
5.83	5.36	393,508	5.60	AZ
4.20	4.03	2,161,370	4.11	CA
5.03	4.54	312,580	4.79	CO
4.68	4.05	173,445	4.36	CT
6.69	5.25	43,900	5.97	DC
6.62	5.30	52,873	5.96	DE
6.11	5.82	1,091,908	5.97	FL
6.94	6.54	625,219	6.74	GA
5.97	4.95	80,709	5.46	HI
5.04	4.41	184,889	4.73	IA
5.38	4.55	109,817	4.96	ID
5.98	5.62	678,780	5.80	IL
7.04	6.53	400,716	6.79	IN
6.26	5.54	175,138	5.90	KS
6.15	5.56	263,188	5.86	KY
7.88	7.25	289,800	7.57	LA
3.88	3.48	342,375	3.68	MA
6.18	5.67	346,879	5.92	MD
6.33	5.12	59,728	5.73	ME
6.62	6.19	529,293	6.40	MI
4.85	4.38	325,254	4.61	MN
6.46	5.94	353,119	6.20	MO
9.17	8.31	178,940	8.74	MS
5.40	4.25	55,789	4.82	MT
6.97	6.55	596,437	6.76	NC
5.80	4.55	50,828	5.17	ND
5.95	5.12	123,488	5.54	NE
4.20	3.23	60,327	3.71	NH
4	3.66	503,152	3.83	NJ
5.90	5.03	110,907	5.46	NM
5.70	5.01	171,286	5.35	NV
4.36	4.11	1,075,631	4.23	NY
7.14	6.74	656,808	6.94	OH
7.13	6.48	243,308	6.81	OK
4.60	4.03	204,273	4.31	OR
5.89	5.52	663,470	5.70	PA
5.19	4.01	51,515	4.60	RI
7.24	6.63	284,416	6.93	SC
7.46	6.11	56,872	6.79	SD
6.85	6.35	403,872	6.60	TN
5.56	5.35	1,887,748	5.45	TX
5.45	4.87	232,217	5.16	UT
6.08	5.65	483,476	5.87	VA
4.94	3.39	26,626	4.17	VT
4.64	4.24	421,310	4.44	WA
6.09	5.55	309,792	5.82	WI
7.45	6.35	87,834	6.90	WV
6.61	4.93	31,541	5.77	WY

The tabs show the same 51 rates, one as tiles on a map and one ranked. The tiles show where the high rates are; the ranking shows how far apart the ends are and which states are indistinguishable from the national rate.Note: Rates are infant deaths in 2018 to 2022 over live births in the same years, pooled over the five years, for the 51 jurisdictions. WONDER publishes every state total in full, so no state has a withheld cell.Note: Intervals are 95% intervals on the death counts (gamma for small counts and normal for large ones, the NCHS convention described in the methods note); they treat deaths as independent and leave out differences between counties within a state.Note: WONDER weights infant deaths, so a total can differ from the unweighted number of records by rounding.Source: CDC WONDER linked birth and infant death, 2018-2022; crude rates from full counts

Counties with high rates are concentrated in the South

WONDER names only 261 counties in its linked file, which is too few to map infant mortality. County Health Rankings publishes a rate for every county with at least 20 infant deaths in the period, from the same NCHS vital statistics, and gives 1,206 counties a rate for infant deaths and live births in 2015 to 2021 (Figure 2). That period is not WONDER's, so the two sources are compared before the map is used. Across the 240 large counties that both cover, the two sets of county rates correlate at 0.980 (95% CI 0.974 to 0.985).

Of the mapped counties in the highest tenth of rates, 85.1% are in the South, which holds 49.3% of the mapped counties. Mississippi holds 25 of those counties, more than any other state. The 1,937 gray counties had fewer than 20 infant deaths in the period, which in practice means small counties. Gray is not zero, and the tooltip gives the reason. The key runs from 3.7 to 10.6, the fifth to ninety-fifth percentile of the mapped county rates, and the end colors include the counties beyond those limits. The highest county rates rest on few deaths, so a single county's rate is imprecise and the pattern across many counties is what the map shows.

Figure 2

85.1% of the counties in the highest tenth of infant mortality rates are in the South, which holds 49.3% of the 1,206 counties that publish a rate

Infant deaths per 1,000, by county, County Health Rankings 2024, infant deaths and live births in 2015 to 2021

Loading county values

Infant deaths per 1,000 live births, 2015 to 2021

Values outside 3.7 to 10.6 take the end colors.

No data (3,143 counties)

Select a class to show only those places.

Find a county

Hover or tap a county for its value, or search by name. Zoom with the buttons on the map, then drag to move it.

Counties toward the high end of the key have more infant deaths per birth, and gray hatched counties have no value because they had fewer than 20 infant deaths in the period; the tooltip gives the reason. The map plots 1,206 counties, and 1,937 are gray.Note: County Health Rankings publishes a county's infant mortality rate only from 20 infant deaths in the period, which leaves out most small counties and is the same floor the book uses for death maps. Gray counties are not zero; they are counties where the rate cannot be published.Note: The period is 2015 to 2021, not the 2018 to 2022 of the WONDER figures. Across the 240 large counties the two sources correlate at 0.980.Note: The key runs from 3.7 to 10.6, the fifth to ninety-fifth percentile of the mapped county rates. Counties beyond either end take the end color, so the end colors include the tails of the distribution.Note: Connecticut is shown as its eight legacy counties, the coding of the source. Alaska is drawn. Puerto Rico is not drawn.Source: County Health Rankings 2024 (NCHS mortality and natality counts; window and 20-death rule as in the CHR 2024 technical documentation, see the dataset note), infant deaths and live births in 2015-2021; crude rates from full counts

Infant mortality rises with county deprivation

To place counties on one scale, each census tract carries its Area Deprivation Index national rank, which orders neighborhoods by deprivation with a higher rank meaning more deprived.[3] A county's rank is the average of its tracts' ranks weighted by population, the same measure used in Chapter 1.1, Birthweight and preterm birth. That chapter cuts its quartiles within the larger set of counties that WONDER natality names, while the quartiles here are cut within the counties used below, so quartile edges differ and quartile rates in the two chapters are not directly comparable. The gradient uses the 240 of the 261 named counties that publish a death count in every year from 2018 to 2022. They hold 62.3% of births in the United States. The quarters here are quarters of these large counties, so the most deprived quarter is relative to large counties and not to the nation. Their ranks run from 3 to 84, while 712 counties in the country rank above the highest of them. Those counties are home to 3.3% of residents, and every one has fewer than 250,000 residents, so WONDER does not name them. The most deprived large county is less deprived than the most deprived places in the nation, which is part of why the County Health Rankings check below matters.

A county-year with fewer than 10 deaths is withheld, which makes a county's published years its high years. Pooling a county over only those years would overstate its rate, so a county with any withheld year is left out whole. That removes 21 counties, which hold 2.6% of births in the named counties and account for 44 withheld county-years. Each of those holds fewer than 10 deaths, so together they could hold at most 0.6% of infant deaths in the named counties. The wider problem of what suppression leaves out of death data is the subject of Chapter 10.5, Suppressed counties in death data.

The rate rises across the quarters of counties, from 3.9 (95% CI 3.7 to 4.1) in the least deprived to 7.2 (95% CI 6.7 to 7.6) in the most deprived (Figure 3). The difference is 3.3 (95% CI 2.8 to 3.8) deaths per 1,000, and the rate in the most deprived quarter is 1.9 (95% CI 1.7 to 2.0) times the rate in the least deprived. Across all of these counties the rate moves with the rank, with a births-weighted correlation of 0.80 (95% CI 0.73 to 0.86) and a slope of 0.63 (95% CI 0.54 to 0.71) deaths per 1,000 for each 10-point step in the rank.

A second source reaches smaller counties. County Health Rankings rates for 2015 to 2021 cover 1,206 counties of every size that reach the floor of 20 deaths. In tenths of those counties the rate is 4.0 (95% CI 3.8 to 4.2) in the least deprived tenth and 8.8 (95% CI 8.1 to 9.5) in the most deprived, with a correlation of 0.76 (95% CI 0.71 to 0.80). The line is not monotone: it rises over the lower deciles and dips across the eighth and ninth before the most deprived tenth. The interval is wider in the most deprived tenth, whose counties have fewer births.

Figure 3

Infant mortality rises from 3.9 per 1,000 in the least deprived quarter of large counties to 7.2 in the most deprived

Infant deaths per 1,000 by county deprivation, WONDER 2018 to 2022 for the large counties and County Health Rankings 2015 to 2021 for all counties with a rate

Across 240 large counties the infant mortality rate moves with the deprivation rank, a correlation of 0.80

Dot area: births, 2018 to 202251,000180,000510,000

Dots drift up from left to right and the quartile means follow them. Each dot is a county, with area in proportion to its births; the line plots the births-weighted rate in each quarter of counties with a 95% interval from a bootstrap over counties.

Show data

Data for Infant mortality rises from 3.9 per 1,000 in the least deprived quarter of large counties to 7.2 in the most deprived, Large counties, 2018 to 2022
adi	births	conf_high	conf_low	county	imr
27.27	24712	5.68	3.95	Ada County, ID	4.82
31.50	30996	6.27	4.63	Adams County, CO	5.45
7.82	87316	3.81	3.04	Alameda County, CA	3.42
60.06	61976	6.97	5.71	Allegheny County, PA	6.34
67.85	26159	8.09	6.05	Allen County, IN	7.07
37.23	18908	6.14	4.06	Anchorage Borough, AK	5.02
26.31	34328	5.23	3.80	Anne Arundel County, MD	4.52
41.11	20680	5.51	3.63	Anoka County, MN	4.50
25.25	37521	5.53	4.12	Arapahoe County, CO	4.82
54.06	13899	7.64	4.95	Atlantic County, NJ	6.19
42.28	47439	7.24	5.79	Baltimore County, MD	6.51
64.94	37283	9.78	7.87	Baltimore city, MD	8.82
64.57	30340	7.68	5.83	Bell County, TX	6.76
19.42	45255	3.32	2.34	Bergen County, NJ	2.83
60.09	22847	7.10	5.07	Berks County, PA	6.08
54.44	33665	5.94	4.40	Bernalillo County, NM	5.17
59.17	130037	6.54	5.69	Bexar County, TX	6.11
49.43	23485	6.16	4.31	Brazoria County, TX	5.24
48.90	25720	7.23	5.29	Brevard County, FL	6.26
34.02	27992	5.09	3.55	Bristol County, MA	4.32
31.09	91577	5.39	4.48	Bronx County, NY	4.94
40.97	105205	5.56	4.69	Broward County, FL	5.12
29.71	28196	4.12	2.73	Bucks County, PA	3.37
40.10	22548	4.61	2.97	Burlington County, NJ	3.73
58.33	21858	8.50	6.23	Butler County, OH	7.37
76.41	14759	13.47	9.97	Caddo Parish, LA	11.72
54.47	30660	6.48	4.80	Camden County, NJ	5.64
84.05	30306	6.10	4.46	Cameron County, TX	5.28
35.04	24786	7.41	5.42	Charleston County, SC	6.41
56.20	18040	8.44	5.97	Chatham County, GA	7.21
26.68	27190	4.92	3.39	Chester County, PA	4.16
40.91	19995	7.02	4.88	Chesterfield County, VA	5.95
39.24	128486	5.71	4.92	Clark County, NV	5.32
26.64	27580	4.93	3.41	Clark County, WA	4.17
71.44	18045	9.94	7.24	Clayton County, GA	8.59
59.97	13801	8.41	5.57	Cleveland County, OK	6.88
37.38	44285	6.11	4.73	Cobb County, GA	5.42
26.55	59079	4.58	3.55	Collin County, TX	4.06
12.71	58952	4.22	3.24	Contra Costa County, CA	3.73
47.08	282978	6.27	5.70	Cook County, IL	5.99
30.73	13937	6.02	3.66	Cumberland County, ME	4.74
72.53	26502	9.36	7.17	Cumberland County, NC	8.26
69.33	66965	8.62	7.27	Cuyahoga County, OH	7.94
35.84	25220	4.34	2.83	Dakota County, MN	3.53
51.84	184635	6.68	5.96	Dallas County, TX	6.32
37.44	28463	5.66	4.04	Dane County, WI	4.85
62.88	16619	7.79	5.33	Dauphin County, PA	6.56
38	49796	7.43	5.99	Davidson County, TN	6.71
26.64	24783	5.75	4.01	Davis County, UT	4.88
44.32	51244	7.61	6.17	DeKalb County, GA	6.89
47.79	31972	7.26	5.51	Delaware County, PA	6.38
31.79	52331	4.76	3.65	Denton County, TX	4.20
21.31	45889	5.36	4.10	Denver County, CO	4.73
16.41	43900	6.69	5.25	District of Columbia, DC	5.97
55.92	40205	6.94	5.40	Douglas County, NE	6.17
34.30	49162	4.39	3.30	DuPage County, IL	3.84
41.88	20648	6.90	4.82	Durham County, NC	5.86
55.54	63717	8.47	7.10	Duval County, FL	7.78
61.83	28385	9.38	7.25	East Baton Rouge Parish, LA	8.31
32.73	45669	6.25	4.88	El Paso County, CO	5.56
74.50	56931	4.90	3.81	El Paso County, TX	4.36
62.29	47598	6.99	5.57	Erie County, NY	6.28
74.57	13589	9.12	6.18	Erie County, PA	7.65
62.76	18763	9.27	6.72	Escambia County, FL	7.99
21.97	42043	4.40	3.22	Essex County, MA	3.81
33.03	49864	5.40	4.19	Essex County, NJ	4.79
14.29	64587	4.28	3.33	Fairfax County, VA	3.81
26.85	49089	4.33	3.24	Fairfield County, CT	3.79
55.11	18798	6.89	4.71	Fayette County, KY	5.80
62.43	22019	9.61	7.19	Forsyth County, NC	8.40
37.63	45977	5	3.79	Fort Bend County, TX	4.39
55.13	89264	8.11	6.97	Franklin County, OH	7.54
46.34	70267	6.50	5.36	Fresno County, CA	5.93
36.01	61856	7.68	6.36	Fulton County, GA	7.02
50.28	19552	6.29	4.25	Galveston County, TX	5.27
73.71	22242	8.41	6.16	Genesee County, MI	7.28
68.78	16516	7.31	4.92	Greene County, MO	6.12
52.19	31893	6.17	4.56	Greenville County, SC	5.36
62.39	29763	9.55	7.45	Guilford County, NC	8.50
41.21	54430	6.31	5.04	Gwinnett County, GA	5.68
33.43	18889	5.80	3.78	Hamilton County, IN	4.71
59.80	52488	8.79	7.25	Hamilton County, OH	8.02
51.80	21724	7.36	5.25	Hamilton County, TN	6.31
54.48	24027	6.25	4.40	Hampden County, MA	5.33
55.59	326538	5.90	5.39	Harris County, TX	5.65
47.60	44945	5.38	4.10	Hartford County, CT	4.74
36.21	75308	5.15	4.17	Hennepin County, MN	4.66
42.82	18663	7.23	4.99	Henrico County, VA	6.11
83.04	69018	5.14	4.13	Hidalgo County, TX	4.64
45.98	85289	7.12	6.03	Hillsborough County, FL	6.58
35.48	20792	4.90	3.14	Hillsborough County, NH	3.94
11.87	57712	6.02	4.82	Honolulu County, HI	5.42
57.80	15979	7.97	5.43	Horry County, SC	6.70
19.35	16518	6.36	4.11	Howard County, MD	5.15
24.79	47913	3	2.09	Hudson County, NJ	2.55
68	14800	8.45	5.74	Ingham County, MI	7.09
64.74	43660	8.04	6.44	Jackson County, MO	7.24
62.60	40646	9.41	7.62	Jefferson County, AL	8.51
19.12	27859	5.23	3.67	Jefferson County, CO	4.45
60.18	47503	6.76	5.36	Jefferson County, KY	6.06
75.11	16350	9.52	6.75	Jefferson County, TX	8.13
60.17	27429	7.40	5.50	Jefferson Parish, LA	6.45
35.27	34859	4.71	3.38	Johnson County, KS	4.04
60.96	14235	6.76	4.27	Kalamazoo County, MI	5.41
45.72	29065	6.06	4.40	Kane County, IL	5.23
51.75	41330	6.13	4.71	Kent County, MI	5.42
52.63	63025	6.17	5	Kern County, CA	5.59
12.92	118597	4.30	3.59	King County, WA	3.95
9.96	177304	3.65	3.11	Kings County, NY	3.38
52.49	26154	6.98	5.10	Knox County, TN	6.04
52.55	17380	6.93	4.63	Lake County, FL	5.70
42.15	34279	4.79	3.43	Lake County, IL	4.11
65.67	27602	7.86	5.90	Lake County, IN	6.88
55.73	18657	6.41	4.31	Lancaster County, NE	5.36
49.56	34889	6.56	4.96	Lancaster County, PA	5.76
37.21	15763	6.03	3.80	Lane County, OR	4.82
24.18	15478	5.57	3.41	Larimer County, CO	4.39
47.61	35217	6.44	4.87	Lee County, FL	5.65
54.75	20497	6.85	4.76	Lehigh County, PA	5.81
57.97	14368	11.13	7.94	Leon County, FL	9.54
62.02	16300	7.33	4.88	Lexington County, SC	6.01
64.59	16003	7.19	4.75	Lorain County, OH	5.87
14.23	507627	4.05	3.70	Los Angeles County, CA	3.87
11.94	24624	4.27	2.76	Loudoun County, VA	3.45
67.26	20115	6.38	4.36	Lubbock County, TX	5.37
74.43	25684	10.20	7.87	Lucas County, OH	9.03
75.48	16015	7.11	4.69	Luzerne County, PA	5.81
58.72	44601	5.68	4.36	Macomb County, MI	5.02
53.80	21699	7.07	5	Madison County, AL	6.04
46.74	17713	6.75	4.54	Manatee County, FL	5.65
36.11	253434	5.68	5.10	Maricopa County, AZ	5.39
66.59	17607	8.41	5.91	Marion County, FL	7.16
67.02	69959	8.79	7.45	Marion County, IN	8.12
38.99	20047	4.91	3.12	Marion County, OR	3.94
40.70	73809	5.69	4.66	Mecklenburg County, NC	5.18
42.31	19125	5.32	3.41	Merced County, CA	4.29
42.50	20404	5.97	4.03	Mercer County, NJ	5
37.24	146849	5.11	4.41	Miami-Dade County, FL	4.76
14.53	81044	3.07	2.36	Middlesex County, MA	2.71
29.18	43015	4.40	3.23	Middlesex County, NJ	3.81
66.79	61939	9.02	7.58	Milwaukee County, WI	8.30
72.95	26321	9.38	7.18	Mobile County, AL	8.28
20.24	30024	3.76	2.47	Monmouth County, NJ	3.06
65.30	38357	6.91	5.34	Monroe County, NY	6.13
16.90	28437	5.81	4.17	Monterey County, CA	4.99
18.93	59475	5.05	3.97	Montgomery County, MD	4.51
72.95	31169	9.12	7.12	Montgomery County, OH	8.12
31.41	42442	4.40	3.23	Montgomery County, PA	3.82
43.03	38709	5.19	3.85	Montgomery County, TX	4.52
24.43	38803	4.51	3.27	Multnomah County, OR	3.89
13.81	69152	3.29	2.49	Nassau County, NY	2.89
43.82	30714	7.17	5.40	New Castle County, DE	6.28
48.10	42444	5.94	4.56	New Haven County, CT	5.25
8.92	75763	3.10	2.36	New York County, NY	2.73
14.99	35515	3.39	2.27	Norfolk County, MA	2.79
68.22	21911	6.26	4.33	Nueces County, TX	5.29
43.65	63665	5.28	4.21	Oakland County, MI	4.74
35.14	47818	3.39	2.42	Ocean County, NJ	2.91
66.32	55427	7.28	5.93	Oklahoma County, OK	6.60
67.47	24676	6.31	4.47	Onondaga County, NY	5.39
11.18	163437	3.50	2.95	Orange County, CA	3.22
44.12	82031	6.25	5.21	Orange County, FL	5.73
36.70	26515	4.50	3	Orange County, NY	3.70
51.55	21909	8.34	6.09	Orleans Parish, LA	7.21
47.66	23048	5.38	3.65	Osceola County, FL	4.51
38.83	73930	5.19	4.20	Palm Beach County, FL	4.69
55.44	26164	6.20	4.43	Pasco County, FL	5.31
34.54	31863	4.41	3.06	Passaic County, NJ	3.73
62.40	99523	7.53	6.49	Philadelphia County, PA	7.01
26.23	55649	5.73	4.54	Pierce County, WA	5.14
53.40	51086	6.21	4.91	Pima County, AZ	5.56
50.23	23631	6.63	4.71	Pinal County, AZ	5.67
48.07	38298	6.59	5.06	Pinellas County, FL	5.82
23.13	26014	4.34	2.85	Plymouth County, MA	3.54
62.59	41609	8.18	6.53	Polk County, FL	7.35
55.05	32415	5.70	4.17	Polk County, IA	4.94
33.05	57070	7.60	6.24	Prince George's County, MD	6.92
23.33	31727	5.76	4.20	Prince William County, VA	4.98
42.93	34996	6.14	4.60	Providence County, RI	5.37
68.10	25254	10.33	7.97	Pulaski County, AR	9.15
16.43	127498	4.01	3.35	Queens County, NY	3.68
46.60	34908	6.68	5.07	Ramsey County, MN	5.87
64.44	23223	8.14	5.98	Richland County, SC	7.06
15.94	25520	4.99	3.40	Richmond County, NY	4.19
28.37	139031	4.83	4.12	Riverside County, CA	4.47
21.10	29748	3.53	2.28	Rockland County, NY	2.86
41.48	21292	7.36	5.23	Rutherford County, TN	6.29
27.87	92812	5.60	4.68	Sacramento County, CA	5.14
27.27	77022	5.92	4.88	Salt Lake County, UT	5.40
31.95	137256	5.86	5.07	San Bernardino County, CA	5.46
13.98	190765	3.87	3.33	San Diego County, CA	3.60
3.15	39750	3.17	2.16	San Francisco County, CA	2.67
28.64	49351	6.08	4.78	San Joaquin County, CA	5.43
3.18	39199	3.41	2.35	San Mateo County, CA	2.88
17.02	27310	4.86	3.34	Santa Barbara County, CA	4.10
5.05	100305	3.03	2.39	Santa Clara County, CA	2.71
68.53	33214	7.85	6.06	Sedgwick County, KS	6.95
40.38	22970	6.59	4.65	Seminole County, FL	5.62
66.30	63231	9.03	7.61	Shelby County, TN	8.32
17.55	48396	4.04	2.98	Snohomish County, WA	3.51
20.56	24894	5.20	3.56	Solano County, CA	4.38
14.25	22266	3.82	2.33	Sonoma County, CA	3.01
66.48	19748	6.44	4.39	Spartanburg County, SC	5.42
40.64	29031	5.14	3.61	Spokane County, WA	4.37
44.15	21156	5.86	3.97	St. Charles County, MO	4.92
70.57	14336	10.17	7.13	St. Clair County, IL	8.65
71.71	16710	9.18	6.50	St. Joseph County, IN	7.84
53.57	54322	6.56	5.26	St. Louis County, MO	5.91
70.84	18927	10.39	7.68	St. Louis city, MO	9.03
50.80	16350	6.43	4.15	St. Lucie County, FL	5.20
33.77	36279	5.78	4.31	Stanislaus County, CA	5.04
71.61	19961	7.58	5.35	Stark County, OH	6.46
16.54	42713	4.50	3.32	Suffolk County, MA	3.91
19.74	77073	4.32	3.44	Suffolk County, NY	3.88
66.08	28116	7.07	5.24	Summit County, OH	6.15
48.92	136253	6.25	5.44	Tarrant County, TX	5.84
30.13	15251	6.53	4.16	Thurston County, WA	5.25
27.39	77756	4.53	3.63	Travis County, TX	4.08
50.21	33845	5.81	4.30	Tulare County, CA	5.05
64.81	43862	8.17	6.56	Tulsa County, OK	7.36
28.09	33101	4.57	3.22	Union County, NJ	3.90
26.08	58954	5.36	4.24	Utah County, UT	4.80
14.46	43372	4.43	3.27	Ventura County, CA	3.85
38.95	26879	6.51	4.72	Virginia Beach city, VA	5.62
55.90	24368	6.61	4.72	Volusia County, FL	5.66
32	64176	5.88	4.75	Wake County, NC	5.31
21.83	30945	4.47	3.10	Washington County, OR	3.78
28.88	25572	6.64	4.78	Washoe County, NV	5.71
40.20	16820	6.77	4.46	Washtenaw County, MI	5.53
34.74	19067	5.69	3.70	Waukesha County, WI	4.62
72.84	109697	10.22	9.05	Wayne County, MI	9.64
73.52	22421	5.87	4.03	Webb County, TX	4.95
32.31	22285	4.77	3.09	Weld County, CO	3.86
20.19	49530	4.29	3.22	Westchester County, NY	3.76
66.04	14352	6.78	4.30	Westmoreland County, PA	5.43
43.71	35331	5.87	4.38	Will County, IL	5.12
31.02	35958	4.39	3.12	Williamson County, TX	3.75
76.98	16888	9.41	6.70	Winnebago County, IL	8.05
35.79	42128	4.72	3.49	Worcester County, MA	4.11
58.42	23830	5.62	3.87	York County, PA	4.74

The first tab shows the large counties behind the quartile means in the title. The second tab shows the rate by decile for every county with a published rate from a second source, including smaller counties.Note: The counties are the 240 of 261 named counties (at least 250,000 residents) with a published death count in every year; they hold 62.3% of births in the United States. The other 21 named counties have a withheld year (44 withheld county-years in all, each of 1 to 9 deaths) and are left out whole, not pooled over their published years.Note: A county's deprivation rank is the population-weighted mean of the Area Deprivation Index national ranks of its census tracts (1 is least deprived, 100 most), weighted by 2019-2023 tract population. Quartiles hold equal numbers of counties, so the most deprived quarter is relative to large counties and not to the nation.Note: Quartile means are births-weighted. Intervals are 95% intervals from a bootstrap over counties (replicates and seed in the methods note).Note: The second tab uses County Health Rankings rates for counties with at least 20 infant deaths in 2015 to 2021, so it leaves out the smallest counties, and its deciles are deciles of the counties that publish.Source: CDC WONDER linked birth and infant death, 2018-2022, and Area Deprivation Index 2023; crude rates from full counts, births-weighted (population-weighted); second tab: County Health Rankings 2024, 2015-2021

The rise holds within states and within groups of mothers

Counties in the South have higher deprivation ranks and higher rates, so the rise could come from differences between states alone. Comparing counties inside the same state, with a fixed effect for each state, the slope is 0.62 (95% CI 0.47 to 0.84) deaths per 1,000 for each 10-point step, nearly the same as across all counties (Figure 4). It is also nearly the same when only births in 2018 and 2019 are used, at 0.62 (95% CI 0.52 to 0.71), the only years for which WONDER reports the mother's race.

For births to white mothers, in the 203 counties that publish them in both years and hold 93.9% of those births, the slope is 0.36 (95% CI 0.29 to 0.44). For births to Black mothers, in the 115 counties that do and hold 82.5% of those births, it is 0.82 (95% CI 0.62 to 1.01). The white slope is smaller than the slope for all births, and the Black slope is larger than the white slope. Counties with higher ranks also have a larger share of births to Black mothers, 11.1% of births in the least deprived quarter and 31.1% in the most deprived in 2018 and 2019. The slope for all births therefore combines a rise within each group with a shift in the mix of mothers. A slope across counties describes places. It does not say that a family moved to a less deprived county would see a different outcome.

Figure 4

The rise with county deprivation holds within states and for births to white mothers and to Black mothers, at 0.63 deaths per 1,000 for each 10-point step across all births

Change in infant deaths per 1,000 for each 10-point rise in county deprivation rank (births-weighted slope) with 95% intervals, counties of 250,000 residents or more

Show data

Data for The rise with county deprivation holds within states and for births to white mothers and to Black mothers, at 0.63 deaths per 1,000 for each 10-point step across all births
conf_high	conf_low	group	label	n	slope
0.715	0.544	All births	All births, 2018 to 2022 (240 counties)	240	0.631
0.840	0.467	All births	All births, 2018 to 2022, within states (44 states)	240	0.624
0.709	0.518	All births	All births, 2018 and 2019 (240 counties)	240	0.619
0.440	0.289	White	White mothers, 2018 and 2019 (203 counties)	203	0.362
1.01	0.617	Black	Black mothers, 2018 and 2019 (115 counties)	115	0.817

Every dot lies to the right of zero, and the three rows for all births are close together. The slope for births to white mothers is smaller than the slope for all births, and the dot for Black mothers lies furthest right. The first row is the slope of the main figure; the others change the period, add state fixed effects, or restrict to births to white or to Black mothers.Note: The slope is the births-weighted regression slope of the county rate on the county deprivation rank, multiplied by ten. Intervals come from a bootstrap over counties, except the within-states row, which resamples whole states because the fixed effects pool counties within a state.Note: Race rows use WONDER's single-race groups of any ethnicity and the 240 counties, restricted to the counties that publish the group in both 2018 and 2019: 203 counties for white mothers (93.9% of their births in the counties used) and 115 for Black mothers (82.5%).Note: Counties with a higher deprivation rank also have a larger share of births to Black mothers, 11.1% of births in the least deprived quartile and 31.1% in the most deprived (2018 and 2019), so the slope for all births mixes the rise within each group with the shift in the mix of mothers. A county slope describes places, not individual mothers.Source: CDC WONDER linked birth and infant death, 2018-2022 (mother's race 2018-2019), and Area Deprivation Index 2023; crude rates from full counts, births-weighted (population-weighted)

The Black-white gap appears in every state that publishes both groups

The linked file reports the mother's race only for 2018 and 2019, and WONDER counts mothers by single race, with Hispanic mothers included in each group. In those years the rate was 10.3 (95% CI 10.1 to 10.5) deaths per 1,000 births to Black mothers, 4.7 (95% CI 4.7 to 4.8) for white mothers and 3.9 (95% CI 3.7 to 4.1) for Asian or Pacific Islander mothers, against 5.6 for all mothers (Figure 5). The Black rate is 2.2 (95% CI 2.1 to 2.2) times the white rate, a difference of 5.6 (95% CI 5.4 to 5.8) deaths per 1,000. The Black and white rates are the two printed in Chapter 1.1, Birthweight and preterm birth, computed from the same state files.

WONDER withholds a state-year cell with fewer than 10 deaths. The withheld cells hold 1.0% of births to Black mothers, 0.1% of births to white mothers and 6.7% of births to Asian or Pacific Islander mothers, so those rates describe almost all of the births in each group. For American Indian or Alaska Native mothers the situation differs. WONDER withholds 66 of the 102 state-year cells, and the published cells hold only 65.6% of their births. A pooled rate over those cells would describe the states with the most deaths, so none is shown.

Figure 5

Infant mortality in 2018 and 2019 was 10.3 per 1,000 for Black mothers and 4.7 for white mothers, a ratio of 2.2

Infant deaths per 1,000 by mother's single race, any ethnicity, United States, 2018 and 2019, with 95% intervals

Show data

Data for Infant mortality in 2018 and 2019 was 10.3 per 1,000 for Black mothers and 4.7 for white mothers, a ratio of 2.2
conf_high	conf_low	label	n	race	rate
5.68	5.57	All mothers	7,539,252	All	5.63
10.49	10.14	Black (any ethnicity)	1,255,629	Black	10.32
4.78	4.66	White (any ethnicity)	5,617,093	White	4.72
4.08	3.74	Asian or Pacific Islander (any ethnicity)	524,395	Asian	3.91

The dot for Black mothers lies furthest right and the dot for Asian or Pacific Islander mothers furthest left, and no interval touches another. Each dot is a pooled crude rate from state counts. American Indian or Alaska Native mothers are not shown because WONDER withholds too many of their state-years.Note: WONDER counts mothers by single race and includes Hispanic mothers in each group, so the white group here is not the non-Hispanic white group of County Health Rankings. Mother's race is reported in the linked file only for 2018 and 2019.Note: A state-year cell with fewer than 10 deaths is withheld (1 to 9 deaths) and leaves both deaths and births. The withheld cells hold 1.0% of births to Black mothers, 0.1% of births to white mothers and 6.7% of births to Asian or Pacific Islander mothers.Note: For American Indian or Alaska Native mothers WONDER withholds 66 of 102 state-year cells and the published cells hold only 65.6% of their births, so a pooled rate would describe the states with the most deaths. No rate is shown.Note: Intervals are gamma or normal intervals on the death counts; they treat deaths as independent and leave out differences between states.Source: CDC WONDER linked birth and infant death, 2018-2019, mother's race (crude rates from full counts)

Infants of Black mothers died at a higher rate than infants of white mothers in each of the 36 states that publish both groups in both years, which hold 98.0% of births to Black mothers (Figure 6). In none of them does the interval for one group touch the interval for the other. The ratio has a median of 2.1 across these states. It is smallest in Mississippi, at 1.7 (95% CI 1.4 to 1.9), and largest in Delaware, at 3.2 (95% CI 2.3 to 4.7). Mississippi has the smallest ratio and also the highest white rate of the states shown, 6.7 (95% CI 5.8 to 7.5). The lowest white rate is 3.2 (95% CI 2.9 to 3.5), in New Jersey. The white rate itself therefore differs across states, and the state ranking in Figure 1 is not only a difference in racial composition.

Figure 6

Black mothers' infants died at a higher rate than white mothers' in all 36 states that publish both, by a median ratio of 2.1

Infant deaths per 1,000 by mother's single race, any ethnicity, 36 states, 2018 and 2019, with 95% intervals, ordered by the Black-white difference

White mothers (any ethnicity)
Black mothers (any ethnicity)

Show data

Data for Black mothers' infants died at a higher rate than white mothers' in all 36 states that publish both, by a median ratio of 2.1
black	hi_b	hi_w	lo_b	lo_w	n_b	n_w	state	white
11.67	14.62	4.78	9.18	2.66	6,429	13,325	Delaware	3.60
12.73	13.79	5.02	11.68	4.35	44,064	163,307	Michigan	4.68
12.66	14.45	5.41	10.87	4.56	15,162	103,924	Wisconsin	4.98
12.29	16.08	5.35	9.21	4.05	4,312	42,773	Nebraska	4.70
12.97	13.96	5.86	11.97	5.22	50,431	208,964	Ohio	5.54
12.13	13.09	5.19	11.18	4.60	51,108	213,812	Illinois	4.90
11.72	12.83	5.24	10.61	4.25	36,444	73,958	South Carolina	4.75
12.15	15.23	5.89	9.56	4.74	6,173	62,047	Kansas	5.32
12.69	14.83	6.76	10.56	5.63	10,713	73,285	Oklahoma	6.19
11.93	13.07	6.03	10.78	5.18	34,960	121,143	Tennessee	5.60
11.16	11.97	5.39	10.34	4.69	64,533	157,420	North Carolina	5.04
10.63	11.25	4.81	10.01	4.34	106,859	317,717	Florida	4.58
10.41	13.25	4.92	8.05	3.90	6,338	65,737	Iowa	4.41
10.64	11.30	5.36	9.97	4.63	93,071	145,932	Georgia	5
10.60	11.53	5.29	9.68	4.68	47,243	207,572	Pennsylvania	4.99
10.99	12.06	6.16	9.92	5.10	36,953	76,765	Alabama	5.63
11.47	13.18	6.81	9.76	5.50	15,082	55,070	Arkansas	6.16
9.34	10.20	4.48	8.48	3.60	48,404	80,981	Maryland	4.04
9.43	11.17	4.49	7.69	3.80	11,984	131,533	Washington	4.14
9.77	10.36	5	9.17	4.65	105,253	604,692	Texas	4.83
10.37	11.66	5.88	9.07	5.03	23,828	116,241	Missouri	5.45
8.11	9.06	3.53	7.16	2.94	34,767	141,428	New Jersey	3.23
10.82	11.76	6.54	9.88	5.38	46,868	68,003	Louisiana	5.96
8.63	9.98	4.29	7.28	3.52	18,199	101,548	Minnesota	3.91
10.64	11.98	6.42	9.31	5.59	22,926	134,146	Indiana	6.01
9.06	13.09	5.77	6.02	3.61	3,092	16,093	Rhode Island	4.60
9.18	10.06	5.17	8.30	4.43	45,536	133,860	Virginia	4.80
7.96	8.56	3.81	7.37	3.38	87,384	307,616	New York	3.60
10.99	12.13	7.45	9.86	5.85	32,561	39,548	Mississippi	6.65
9.33	11.13	5.79	7.53	4.55	11,042	51,823	Nevada	5.17
9.20	10.97	5.47	7.43	4.70	11,303	132,097	Arizona	5.09
8.16	8.89	4.21	7.43	3.90	58,843	677,920	California	4.06
9	10.74	5.50	7.26	4.58	11,443	92,669	Kentucky	5.04
7.66	9.46	4.28	6.12	3.23	11,231	52,490	Connecticut	3.75
8.25	10.42	4.97	6.43	4.17	8,488	109,155	Colorado	4.57
6.83	7.97	3.90	5.68	3.18	20,073	104,559	Massachusetts	3.54

In every row the filled dot for Black mothers lies to the right of the open dot for white mothers. The white rate also varies by state, from 3.2 to 6.7.Note: Only states that publish infant deaths for both groups in both years appear; they hold 98.0% of births to Black mothers. A state-year cell of 1 to 9 deaths is withheld, and a state is shown only when no cell of either group is withheld, so states with few Black births are absent.Note: WONDER counts mothers by single race and includes Hispanic mothers in each group. Intervals are gamma or normal intervals on the death counts and leave out differences between counties within a state.Source: CDC WONDER linked birth and infant death, 2018-2019, mother's race (crude rates from full counts)

A rate for a racial group in a state averages over mothers whose circumstances differ greatly, so these comparisons do not identify which circumstances matter. Chapter 1.1, Birthweight and preterm birth reports studies of income support and insurance during pregnancy and the birth outcomes that precede these deaths.

Age at death is published for only a few counties

WONDER's county file splits infant deaths into five age groups, from under an hour to the end of the first year. It withholds each county-year-age cell with fewer than 10 deaths, which is 4,328 of the 6,525 cells for the named counties. Only 14 counties publish every cell in every year (Figure 7). They are among the largest counties and hold 23.6% of births in the named counties. The age groups cannot be summed for any other county without filling in withheld cells, so this section covers these counties and no others.

In these counties the neonatal rate is 3.6 (95% CI 3.1 to 4.1) and the postneonatal rate is 1.6 (95% CI 1.4 to 1.9), so neonatal deaths are 68.7% (95% CI 67.4% to 70.2%) of infant deaths, and 42.3% (95% CI 40.5% to 44.2%) occur on the first day of life. Both rates are higher where the deprivation rank is higher. Dividing the 14 counties at the median rank, the neonatal rate in the more deprived group is 1.5 (95% CI 1.2 to 1.8) times the rate in the less deprived group, and the postneonatal rate is 1.6 (95% CI 1.3 to 2.1) times. The intervals overlap, so these counties cannot show whether the postneonatal rate rises faster with deprivation. The comparison of the United States with Europe placed the American disadvantage in the postneonatal period, among infants of lower socioeconomic status.[1] These counties have no European comparison and too few observations to test that.

Figure 7

Neonatal deaths made up 68.7% of infant deaths in the 14 counties that publish every age group, and both rates are higher where deprivation is higher

Infant deaths per 1,000 by age at death, 14 counties of 250,000 residents or more, 2018 to 2022, ordered from the least to the most deprived county rank

Neonatal (under 28 days)
Postneonatal (28 to 364 days)

Show data

Data for Neonatal deaths made up 68.7% of infant deaths in the 14 counties that publish every age group, and both rates are higher where deprivation is higher
age	conf_high	conf_low	county	n	rate
Neonatal (under 28 days)	2.69	2.21	Orange County, CA (rank 11)	163,437	2.45
Postneonatal (28 to 364 days)	0.880	0.610	Orange County, CA (rank 11)	163,437	0.750
Neonatal (under 28 days)	2.90	2.44	San Diego County, CA (rank 14)	190,765	2.67
Postneonatal (28 to 364 days)	1.06	0.790	San Diego County, CA (rank 14)	190,765	0.920
Neonatal (under 28 days)	2.82	2.53	Los Angeles County, CA (rank 14)	507,627	2.67
Postneonatal (28 to 364 days)	1.30	1.11	Los Angeles County, CA (rank 14)	507,627	1.20
Neonatal (under 28 days)	2.73	2.18	Queens County, NY (rank 16)	127,498	2.45
Postneonatal (28 to 364 days)	1.42	1.03	Queens County, NY (rank 16)	127,498	1.22
Neonatal (under 28 days)	4.27	3.61	San Bernardino County, CA (rank 32)	137,256	3.94
Postneonatal (28 to 364 days)	1.71	1.30	San Bernardino County, CA (rank 32)	137,256	1.51
Neonatal (under 28 days)	3.88	3.41	Maricopa County, AZ (rank 36)	253,434	3.65
Postneonatal (28 to 364 days)	1.92	1.59	Maricopa County, AZ (rank 36)	253,434	1.76
Neonatal (under 28 days)	3.56	2.98	Miami-Dade County, FL (rank 37)	146,849	3.27
Postneonatal (28 to 364 days)	1.68	1.29	Miami-Dade County, FL (rank 37)	146,849	1.48
Neonatal (under 28 days)	4.35	3.88	Cook County, IL (rank 47)	282,978	4.11
Postneonatal (28 to 364 days)	2.03	1.71	Cook County, IL (rank 47)	282,978	1.87
Neonatal (under 28 days)	4.34	3.66	Tarrant County, TX (rank 49)	136,253	4
Postneonatal (28 to 364 days)	2.09	1.63	Tarrant County, TX (rank 49)	136,253	1.86
Neonatal (under 28 days)	4.62	4.02	Dallas County, TX (rank 52)	184,635	4.32
Postneonatal (28 to 364 days)	2.20	1.79	Dallas County, TX (rank 52)	184,635	1.99
Neonatal (under 28 days)	5.66	4.71	Franklin County, OH (rank 55)	89,264	5.19
Postneonatal (28 to 364 days)	2.65	2.01	Franklin County, OH (rank 55)	89,264	2.33
Neonatal (under 28 days)	3.91	3.50	Harris County, TX (rank 56)	326,538	3.71
Postneonatal (28 to 364 days)	2.09	1.78	Harris County, TX (rank 56)	326,538	1.94
Neonatal (under 28 days)	4.66	3.95	Bexar County, TX (rank 59)	130,037	4.31
Postneonatal (28 to 364 days)	2.03	1.57	Bexar County, TX (rank 59)	130,037	1.80
Neonatal (under 28 days)	6.65	5.72	Wayne County, MI (rank 73)	109,697	6.18
Postneonatal (28 to 364 days)	3.79	3.10	Wayne County, MI (rank 73)	109,697	3.45

Within each row the neonatal dot lies right of the postneonatal dot, and both dots tend to move right down the page in these 14 counties, the only ones that publish every age cell. Whiskers are 95% intervals on the death counts. Neonatal deaths occur before 28 days of age and postneonatal deaths from that age to the first birthday.Note: WONDER withholds 4,328 of 6,525 county-year-age cells in the named counties (1 to 9 deaths each), so only 14 counties publish every age group in every year: among the largest counties, holding 23.6% of births in the named counties. Counties with any withheld cell are left out whole; no group is summed from published cells alone and nothing is derived from totals.Note: The row label gives the county deprivation rank (1 least deprived, 100 most). WONDER weights infant deaths, so the age groups can differ from a county's total by rounding.Note: Intervals are gamma or normal intervals on each county's death count; they treat deaths as independent.Source: CDC WONDER linked birth and infant death, 2018-2022, by age at death; crude rates from full counts

What these data cannot show

The county gradient describes the 240 largest counties, which hold 62.3% of births. WONDER pools the rest by state. The County Health Rankings check reaches smaller counties but leaves out those that do not reach 20 deaths in the period, and the counties just above that floor have the least precise rates on the map. The county rates describe counties that publish a figure, which are not a sample of all counties, and the age-at-death figure covers only 14 of them.

Sources and periods differ, and each is named where it appears. WONDER covers 2018 to 2022 for states and counties and 2018 and 2019 for mother's race, and County Health Rankings covers 2015 to 2021. WONDER's race groups are single races that include Hispanic mothers, so its white group is not the non-Hispanic white group of other sources, and Hispanic origin is not in the files used here. American Indian or Alaska Native mothers are not shown.

The Area Deprivation Index understates deprivation in high-cost cities (Chapter 10.2, The anatomy of a deprivation index) and draws on the American Community Survey for 2019 to 2023, while the deaths are from 2018 to 2022. A county's rank averages over tracts that differ within the county, and it describes no family's circumstances. Patterns across counties and states are patterns of places, not of individual infants, a limit known as ecological inference.

Finally, the files carry no cause of death, no gestational age or birthweight, and no information on mothers beyond race, so nothing here identifies a mechanism. The rates are crude period rates, and 2020 to 2022 include the pandemic. Intervals for state and race rates treat deaths as independent and leave out differences between places within each rate, while the county figures resample whole counties.

Data sources

CDC WONDER linked birth and infant deathCDC WONDER linked birth and infant death, state totals and race, county totals and age at death, 2018 to 2022 (mother's race 2018 and 2019 only)Years: 2018-2022 · Weights: none (full counts; crude rates) · License: Public domain (NCHS, CDC); WONDER data-use restrictions apply
Area Deprivation IndexNeighborhood Atlas Area Deprivation Index 2023 (v4.0.1), tract national rank, averaged to counties with 2019-2023 tract populationYears: 2023 release (version 4.0.1; built on ACS 2019-2023) · Weights: 2019-2023 tract population · License: Free for non-commercial use; cite the Neighborhood Atlas and Kind and Buckingham
County Health RankingsCounty Health Rankings 2024, infant mortality (infant deaths per 1,000 live births, 2015 to 2021), counties with at least 20 infant deathsYears: 2024 release · Weights: births (County Health Rankings denominator) · License: CC BY 4.0 (University of Wisconsin Population Health Institute)

All data sources

Methods

This chapter compares infant deaths per 1,000 live births across states, counties, groups of mothers by race and ages at death, using CDC WONDER linked birth and infant death records for 2018 to 2022. The rates are crude, with no adjustment for the mother's age or other characteristics. County rates cover only counties that WONDER names (250,000 residents or more) and that publish a death count in every year, so the 21 named counties with a withheld year are left out. Mother's race is reported only for 2018 and 2019, and the county map and the all-county check use County Health Rankings rates for 2015 to 2021, a different source and period.

What is counted and for which years

Infant mortality is the number of infant deaths (before the first birthday) per 1,000. Rates are crude: nothing is adjusted for the mother's age or other characteristics.

Counts come from CDC WONDER linked birth and infant death records, which link death certificates to birth certificates; a death is assigned to the year of death and divided by live births in the same year. WONDER weights infant deaths, so counts can differ from the number of records, and age groups from a total, by rounding.

State rates pool 2018 to 2022 over the 51 jurisdictions, whose totals have no withheld cell. The 2021 state file reproduces the national rate and the highest and lowest state in the NCHS report for that year (5.44 per 1,000 nationally).

Figure explained here: Figure 1

Which counties are included

County rates cover the counties that WONDER names (250,000 residents or more; WONDER pools every other county in a state into one Unidentified Counties row) and use only counties with a published death count in every year 2018 to 2022: a county-year with 1 to 9 deaths is withheld, a county's published years are its high years, and pooling over them would bias the rate upward. A withheld cell is missing; nothing is derived from totals minus published cells. The 21 named counties with a withheld year are left out whole.

Figure explained here: Figure 3

Why mother's race and age at death cover fewer places

Mother's race comes from the linked file for 2018 and 2019, the only years it is reported, as single race of any ethnicity; a state-year cell of 1 to 9 deaths is withheld and leaves both deaths and births, a group's national rate pools the published state-years, and Black and white rates by state use states that publish both groups in both years. American Indian or Alaska Native mothers are not shown because too few of their state-years are published.

Age at death uses the county file, in which the five age groups (under 1 hour, 1 to 23 hours, 1 to 6 days, 7 to 27 days, 28 to 364 days) are each withheld below 10 deaths; neonatal is the first four groups and postneonatal the last, and only counties that publish all five groups in every year are used.

Figures explained here: Figure 5, Figure 6 and Figure 7

The county map and the all-county check use County Health Rankings

The county map and the all-county gradient use County Health Rankings 2024, whose infant mortality rate covers 2015 to 2021 and is published only from 20 deaths (window and rule as in the County Health Rankings 2024 technical documentation and the dataset note; as a consistency check, its denominators run about one percent above the 2016 to 2022 births behind its low birthweight measure, as 2015 to 2021 births would).

Figures explained here: Figure 2 and Figure 4

How counties are ranked and grouped

A county's deprivation rank is the population-weighted mean of the Area Deprivation Index national ranks of its census tracts, weighted by 2019-2023 tract population; Connecticut tracts are assigned to the eight legacy counties. Quartiles and deciles hold equal numbers of counties. Quartile and decile means are births-weighted means of county rates (pooled rates).

Figure explained here: Figure 3

How uncertainty is measured

State rates carry gamma (fewer than 100 deaths) or normal (100 or more) intervals on the death count, the NCHS convention. Ratios of two crude rates carry log-normal intervals on the two death counts and differences carry normal intervals.

Means, differences, ratios, correlations and slopes across counties carry 95% percentile intervals from a bootstrap that resamples whole counties (2,000 replicates, seed 12345); the state fixed-effects slope resamples whole states, and so does each region's pooled rate, within the states of that region; a group needs at least five states, and the Northeast, with nine, has the roughest interval; the ratio of the South to the other states resamples the states of each group separately (seeds 12345 and 12346).

References

Chen, Alice; Oster, Emily; Williams, Heidi (2016). Why Is Infant Mortality Higher in the United States than in Europe?. American Economic Journal: Economic Policy 8(2): 89-124. doi:10.1257/pol.20140224
Ely, Danielle M.; Driscoll, Anne K. (2023). Infant Mortality in the United States, 2021: Data From the Period Linked Birth/Infant Death File. National Vital Statistics Reports 72(11). doi:10.15620/cdc:131356
Kind, Amy J. H.; Buckingham, William R. (2018). Making Neighborhood-Disadvantage Metrics Accessible: The Neighborhood Atlas. New England Journal of Medicine 378(26): 2456-2458. doi:10.1056/NEJMp1802313

How to cite

@misc{singh2026infantmortality,
  author = {Singh, Vishal},
  title = {Infant mortality},
  year = {2026},
  url = {https://vishalsingh.org/zipcode/infant-mortality},
  note = {In ZIP Code Destiny. Published 9 October 2026.}
}