18631 ZIP Code — Mifflinville, PA

Columbia County, Pennsylvania

ZIP code 18631 is located in Mifflinville, Pennsylvania, within Columbia County. It covers approximately 1.42 square miles and serves a population of 1,134 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 570.

About ZIP code 18631

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1960s, giving the area an established character. Median home value is $183,600. Owner-occupancy is high at 79%, well above the national average.

Median household income is $51,875. 47% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 24 minutes is near the national average.

Educational attainment is near the national average, with 26% of residents holding a bachelor's degree or higher.

Overall, ZIP code 18631 reflects a community defined by high homeownership and a significant Social Security-dependent population.

1,134

population

1.42

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

18631 ZIP code map

Cities in ZIP code 18631

Below are the cities the US Postal Service accepts for ZIP code 18631. Using any city not on this list may result in mail delivery delays.

City	Status
Mifflinville	Acceptable

Demographics updated 05/2026

Population
Total population	1,134
Population density	799 / sq mi
State FIPS	42
County FIPS	037

Geography
Land area	1.42 sq mi
Water area	0.17 sq mi
Latitude	41.0267
Longitude	-76.2921
Timezone	Eastern (ET)
Area code	570

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	54.1%	47.2%	39.8%
$50k – $100k	31.8%	31.6%	30.8%
$100k – $200k	12.2%	18.0%	22.4%
Over $200k	1.9%	3.3%	7.1%

Demographics & statistics

1,134

Population

799

People per sq mi

46.1

Median age

$51,875

Median household income

$28,760

Per capita income

$183,600

Median home value

$961

Median monthly rent

79.1%

Home ownership

10.6%

Poverty rate

0.0%

Unemployment

438

Housing units

26.3%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

20–24

25–34

35–44

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	196	17.3%
18 and over	938	82.7%
65 and over	227	20.0%
Median age	46.1 years

Race & ethnicity

White 98.5%

Black or African American 1.5%

Group	Count	%
White	1,117	98.5%
Black or African American	17	1.5%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	54.1%	47.2%	39.8%
$50k – $100k	31.8%	31.6%	30.8%
$100k – $200k	12.2%	18.0%	22.4%
Over $200k	1.9%	3.3%	7.1%

Under $10k 11.3%

$10k–$15k 8.5%

$15k–$25k 9.3%

$25k–$35k 4.9%

$35k–$50k 10.5%

$50k–$75k 21.1%

$75k–$100k 6.7%

$100k–$150k 26.1%

$150k–$200k 1.6%

Range	% of households
Under $10k	11.3%
$10k–$15k	8.5%
$15k–$25k	9.3%
$25k–$35k	4.9%
$35k–$50k	10.5%
$50k–$75k	21.1%
$75k–$100k	6.7%
$100k–$150k	26.1%
$150k–$200k	1.6%
Median income	$51,875

Housing

Home values

$50k–$100k 3.1%

$100k–$150k 30.7%

$150k–$200k 25.3%

$200k–$300k 38.1%

$300k–$500k 1.3%

$1M+ 1.5%

Housing overview

Metric	Value
Median home value	$183,600
Median rent / month	$961
Owner occupied	79.1%
Renter occupied	20.9%
Vacant	8.7%
Single-family detached	85.2%
Large apartment buildings	0.0%
Mobile homes	3.1%
Median rooms	5.6
Avg household size (owned)	2.41

Year built

Era	%
2020 or later	0.0%
2010–2019	0.0%
2000–2009	0.0%
1990–1999	3.7%
1980–1989	19.2%
1970–1979	17.6%
1960–1969	22.6%
1950–1959	15.0%
1940–1949	4.3%
1939 or earlier	17.7%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	6.1%
2 bedrooms	33.5%
3 bedrooms	50.5%
4 bedrooms	10.0%
5+ bedrooms	0.0%

Vehicles per household

Vehicles	% of households
No vehicle	17.0%
1 vehicle	17.6%
2 vehicles	49.8%
3 or more	15.6%

Heating fuel

Fuel type	%
Utility gas	1.4%
Electricity	35.8%
Propane / LP gas	1.6%
Fuel oil	55.7%
Wood	5.5%

Households & families

Household type	Count	%
Married-couple family	210	42.5%
Cohabiting couple	44	8.9%
Male householder, no spouse	112	22.7%
Female householder, no spouse	128	25.9%
Households with children under 18	88	17.8%
Households with seniors (65+)	201	40.7%
Average household size	2.30

Marital status

Status	Male	Female
Never married	46.5%	29.6%
Married	41.6%	48.1%
Separated	0.0%	0.0%
Widowed	2.9%	15.7%
Divorced	8.9%	6.5%

Education

Less than 9th grade 0.0%

Some HS, no diploma 2.1%

HS graduate 53.9%

Some college, no degree 8.2%

Associate's degree 9.5%

Bachelor's degree 22.7%

Graduate / professional 3.6%

Metric	%
HS diploma or higher	97.9%
Bachelor's or higher	26.3%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	21	11.9%
Kindergarten	23	13.1%
Elementary school	97	55.1%
High school	24	13.6%
College / grad school	11	6.3%

Employment

Industry of employment

Education & healthcare 42.1%

Arts, food & hospitality 14.3%

Manufacturing 11.9%

Transportation & utilities 7.0%

Professional & management 6.8%

Retail trade 5.9%

Wholesale trade 3.0%

Public administration 3.0%

Finance & real estate 2.3%

Construction 1.9%

Other services 1.7%

Occupation

Category	%
Management, business & arts	33.6%
Service	18.2%
Sales & office	24.1%
Natural resources & construction	3.3%
Production & transportation	20.8%

Employment type

Type	%
Private sector	82.3%
Government	16.3%
Self-employed	1.4%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	87.9%
Carpool	3.1%
Public transit	0.0%
Walk	0.0%
Work from home	8.9%
Other means	0.0%
Avg commute (minutes)	24.0

Poverty

All people 10.6%

Under 18 years 0.0%

18 and over 12.8%

Married-couple families 1.9%

Female-led households 0.0%

Income support

Source	% of households
Social Security	47.2%
Retirement income	22.5%
Supplemental Security	5.1%
Cash public assistance	0.0%
Food stamps / SNAP	5.1%

Health indicators

Condition	%
Obesity	32.6%
High blood pressure	34.8%
High cholesterol	35.0%
Diabetes	10.2%
Heart disease	7.2%
Stroke	3.1%
Asthma	9.7%
Arthritis	29.9%
Kidney disease	3.0%
Pulmonary disease	7.5%
Cancer	8.2%

Behavior / access	%
Smoking	17.1%
Binge drinking	17.8%
No physical activity	22.4%
Less than 7 hrs sleep	32.9%
Depression	20.8%
Fair or poor health	13.2%
Poor mental health	14.2%
Poor physical health	10.5%
No health insurance	9.5%
Visited doctor (checkup)	78.9%
Visited dentist	69.9%
Cholesterol screening	91.2%
Teeth loss	12.4%

Veterans & disability

Veterans	Count	%
Civilian veterans	45	4.8%

Disability	%
Any disability	14.5%
Under 18	0.0%
18–64 years	9.4%
65 and over	42.7%

Health insurance coverage

Type	%
Private insurance	73.5%
Public insurance	29.7%
No insurance	5.1%
Uninsured under 19	0.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	1,093	96.4%
Spanish	0	0.0%
Other Indo-European	0	0.0%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	1,118	98.6%
Born in same state	1,118	98.6%
Born in different state	1,036	91.4%
Foreign born	0	0.0%
Naturalized citizen	16	1.4%
Not a US citizen	16	100.0%

Ancestry

Ancestry	Count	%
French	378	33.3%
Italian	92	8.1%

Ancestry	Count	%
Arab	20	1.8%
Norwegian	13	1.1%

Technology access

Metric	% of households
Computer access	43.6%
Internet access	79.6%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 18631

What city is ZIP code 18631 in?

ZIP code 18631 is primarily assigned to Mifflinville, Pennsylvania.

What county is ZIP code 18631 in?

ZIP code 18631 falls within Columbia County, Pennsylvania.

Does ZIP code 18631 have a large retiree population?

47% of households in ZIP code 18631 receive Social Security income, suggesting a significant retiree or disability population.

What is the typical home value in ZIP code 18631?

The median home value in ZIP code 18631 is $183,600.

What is the population of ZIP code 18631?

ZIP code 18631 has an estimated population of 1,134 residents, with a density of 797 people per square mile.

What is the median household income in ZIP code 18631?

The median household income in ZIP code 18631 is $51,875, below the national median of ~$75,000.

What timezone is ZIP code 18631 in?

ZIP code 18631 observes the EST timezone.