IA: the directory by county and ZIP

45,797
practitioners: 47.6%
have a workplace: 13,339
provider organizations: 13,353
tax records (not added): 100
counties

Sort byHide counties under

The bar is the share with a workplace listed, not the number of practitioners. Ranking by headcount would just rank by population.

County	Practitioners	Has a workplace	Provider orgs	Tax records	ZIPs
+Polk County	9,332	41.1%	2,670	2,804	28
+Johnson County	7,314	45.2%	664	702	12
+Linn County	3,344	45.2%	918	959	16
+Scott County	2,721	46.8%	802	929	11
+Black Hawk County	1,632	45.6%	500	519	8
+Dubuque County	1,523	46.0%	416	472	11
+Story County	1,481	46.0%	292	326	11
+Wapello County	1,427	73.2%	181	151	5
+Cerro Gordo County	1,346	62.6%	278	203	4
+Woodbury County	1,184	39.0%	399	407	16
+Pottawattamie County	1,139	59.4%	289	308	8
+Des Moines County	663	57.0%	181	174	4
+Clinton County	659	38.4%	231	237	6
+Sioux County	608	61.2%	162	163	7
+Clay County	536	56.0%	116	104	2
+Marion County	519	54.7%	128	145	6
+Fayette County	487	72.9%	92	74	8
+Muscatine County	430	53.0%	123	127	3
+Webster County	424	33.0%	213	171	5
+Bremer County	421	48.0%	107	107	5
+Dallas County	376	51.6%	158	195	9
+Marshall County	356	24.2%	104	92	3
+Humboldt County	299	83.3%	70	64	2
+Appanoose County	291	75.6%	89	102	3
+Boone County	280	52.9%	68	72	3
+Crawford County	270	71.1%	78	78	3
+Page County	268	56.3%	109	98	4
+Mahaska County	251	47.0%	70	69	3
+Buchanan County	229	63.8%	66	63	4
+Jasper County	228	39.5%	129	131	5
+Carroll County	217	43.8%	100	108	5
+Cass County	197	40.6%	65	51	4
+Warren County	195	39.0%	90	84	3
+Plymouth County	189	42.9%	78	95	5
+Greene County	170	73.5%	68	60	1
+Lee County	168	28.6%	127	125	5
+Jones County	165	58.2%	71	70	4
+Jefferson County	165	35.2%	120	87	2
+O'Brien County	164	53.0%	68	62	6
+Shelby County	157	53.5%	60	44	4
+Winneshiek County	155	25.8%	62	64	4
+Poweshiek County	147	52.4%	83	86	3
+Buena Vista County	144	30.6%	70	65	4
+Wright County	137	70.1%	84	59	4
+Tama County	134	54.5%	43	45	6
+Union County	130	50.0%	50	51	2
+Washington County	128	40.6%	90	102	4
+Dickinson County	127	41.7%	99	110	5
+Benton County	114	43.0%	74	62	9
+Montgomery County	113	42.5%	61	50	3
+Jackson County	112	32.1%	68	73	4
+Henry County	106	44.3%	96	95	4
+Cherokee County	103	40.8%	59	62	3
+Delaware County	93	59.1%	60	59	4
+Lucas County	90	52.2%	31	24	1
+Wayne County	89	62.9%	30	26	2
+Hardin County	85	43.5%	54	57	5
+(county unknown)	82	11.0%	13	9	24
+Calhoun County	82	51.2%	47	39	3
+Allamakee County	82	47.6%	35	29	5
+Kossuth County	75	40.0%	48	56	7
+Monona County	73	45.2%	48	50	4
+Iowa County	73	42.5%	54	59	6
+Madison County	72	54.2%	47	47	3
+Emmet County	72	26.4%	46	43	3
+Cedar County	72	48.6%	35	37	6
+Decatur County	68	41.2%	40	32	3
+Palo Alto County	65	40.0%	40	33	3
+Keokuk County	63	55.6%	53	50	3
+Floyd County	62	45.2%	60	49	3
+Harrison County	62	37.1%	60	63	6
+Clayton County	61	52.5%	74	46	8
+Grundy County	57	68.4%	46	64	5
+Guthrie County	56	46.4%	48	43	3
+Monroe County	53	66.0%	27	30	1
+Howard County	49	44.9%	35	30	3
+Winnebago County	48	43.8%	58	33	4
+Taylor County	47	74.5%	32	18	3
+Lyon County	47	70.2%	32	20	5
+Ida County	42	57.1%	36	29	3
+Sac County	41	43.9%	43	25	4
+Chickasaw County	41	29.3%	34	40	4
+Clarke County	38	28.9%	42	38	2
+Mills County	38	18.4%	37	40	3
+Hamilton County	33	36.4%	35	31	3
+Hancock County	33	39.4%	28	27	3
+Mitchell County	31	45.2%	36	33	5
+Davis County	28	39.3%	26	25	1
+Fremont County	27	66.7%	19	17	4
+Franklin County	24	29.2%	98	33	3
+Adair County	22	27.3%	31	24	3
+Louisa County	22	36.4%	21	22	4
+Pocahontas County	19	31.6%	39	27	4
+Butler County	19	63.2%	33	28	7
+Ringgold County	19	36.8%	31	14	2
+Van Buren County	19	73.7%	27	16	5
+Adams County	18	11.1%	22	16	1
+Audubon County	15	13.3%	28	31	2
+Osceola County	12	66.7%	21	21	2
+Worth County	3	33.3%	10	14	2

By profession, statewide

Profession	Practitioners	Has a workplace
physician	11,870	70.6%
behavioral-health	8,871	29.3%
advanced-practice	6,640	83.5%
rehab-therapy	5,929	30.3%
pharmacy	3,218	7.2%
dental	2,333	15.6%
chiropractic	2,002	59.1%
nursing	1,725	24.5%
eye-vision	682	72.7%
student	656	11.6%
dietary	637	22.6%
other-clinical	486	32.1%
group	261	68.2%
podiatry	229	79.5%
support	140	7.9%
facility	43	41.9%
emergency-medical	21	47.6%
supplier	20	10.0%
no-taxonomy	17	5.9%
agency	10	10.0%
transport	7	28.6%

Release 2026-08-20. Methodology 0.7.3-draft.

Counts come from the NDH bulk export at the release named above. Organizations are split by record type and never summed: roughly half the Organization file is `ein` tax records that carry an NPI and an address, so adding them to provider organizations roughly doubles the count. Practitioner geography uses the primary address; 14.85% of practitioners list addresses in more than one state and are counted only in the first. Counties are derived from the Census ZCTA-to-county relationship file, taking the county holding the largest share of a ZIP's population; ZIPs with no dominant county are grouped as unknown. Payer organizations carry no address at all and cannot appear in any geography. Profession categories here come from the directory's own Practitioner.qualification taxonomy, not from NPPES. H54 categorises the same practitioners against their NPPES taxonomy and lands 1 to 2 points different per profession as a result: PA physicians read 73.0% here and 74.3% there. Neither is wrong. This view describes what the directory says about itself, which is the right frame for a directory explorer; H54 asks how the directory compares to the federal registry.

Data as JSON: /api/v1/explorer/ia.json. Looking for one provider? Search by name or NPI.