Below, we outline 15 of the richest counties in the United States, according to the U.S. Census Bureau’s SAIPE report from 2016. This is based on median household income and the municipal bonds offered by each.

Keep our glossary of municipal bond terminologies handy to familiarize with different concepts commonly used by municipal investors.

Loudoun County is the wealthiest county in the U.S. with a median household income of $125,900 and less than 4% of the population below the poverty line. The county benefits from its proximity to Washington D.C. and high-paying federal government jobs. Loudoun County is rated AAA by all three rating agencies.

• Name: Loudoun County GO Series A
• CUSIP: 54589TFW7
• Maturity: 12/01/2025
• Coupon: 5%

Located adjacent to Loudoun County, Fairfax County also benefits from the strong economy of the Washington D.C. area. Fairfax County had a very low unemployment rate of 2.8% in 2016.

• Name: Fairfax County VA Water Authority
• CUSIP: 303891B46
• Maturity: 4/01/2024
• Coupon: 5%

Howard County is located between Baltimore and Washington D.C. Fort Meade, home of U.S. Cyber Command, is located just 2 miles across the county line and attracts government contractors for cybersecurity and IT jobs. The county’s GDP grew 3% from 2015 to 2016.

• Name: Howard County Public Improvement Project
• CUSIP: 4425657X9
• Maturity: 2/15/2026
• Coupon: 3%

Located south of Denver, Douglas County boasts the lowest poverty rate in the country at just 3.4%. Median home prices grew 8.3% from 2015 to 2016, which continues to drive the property tax base higher.

• Name: Douglas County School District
• CUSIP: 258885L34
• Maturity: 12/15/2025
• Coupon: 4%

Although Los Alamos County has a small population of 17,785, it has one of the highest education rates in the nation with many residents holding a Master’s degree or a PhD.

• Name: Los Alamos New Mexico Public School District
• CUSIP: 54422NFJ0
• Maturity: 8/1/2025
• Coupon: 3%

Williamson County, located south of Nashville, is another county that is rated AAA by Moody’s. Williamson is one of the fastest-growing counties in the nation, with an estimated 15% rate of growth from 2010 to 2015. Median home values were very high in 2015 at $390,000 indicating residents are willing to pay higher housing costs to live there.

• Name: Williamson County TN General Obligation
• CUSIP: 969872JE1
• Maturity: 4/01/2025
• Coupon: 5%

Arlington County is located directly across the Potomac River from Washington D.C., and it is home to the Arlington National Cemetery and Pentagon. Arlington County has consistently experienced lower unemployment rates than Virginia and the national level, indicating a strong labor market.

• Name: Arlington County Virginia General Obligation
• CUSIP: 041431RU3
• Maturity: 8/15/2025
• Coupon: 5%

Santa Clara County is located in the heart of Silicon Valley, and as a result, many residents work at technology companies with high-paying jobs. Top employers include Google, Apple, Intel, Facebook and Oracle.

• Name: Santa Clara County General Obligation
• CUSIP: 801546NF5
• Maturity: 8/1/2024
• Coupon: 5%

Morris County is located just west of New York City, and it’s one of the wealthiest counties in the country with a median household income of $101,754. The GO bonds are backed by the full faith and credit of the county and ad valorem property taxes.

• Name: Morris County New Jersey General Obligation
• CUSIP: 6180238C2
• Maturity: 1/15/2024
• Coupon: 3%

Heavily populated and wealthy counties do not always receive the highest credit ratings. Such is the case with Nassau County, which has a population of 1.35 million and a median household income of $101,568. Nassau County’s limited general obligation bonds are rated A2 by Moody’s, A+ by S&P, and A by Fitch. Moody’s cites the low general fund and cash balance as their rationale for the lower credit rating.

• Name: Nassau County, New York Limited General Obligation
• CUSIP: 63165TYM1
• Maturity: 4/01/2024
• Coupon: 5%

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San Mateo County is home to several large corporate offices in the pharmaceutical and technology sectors for companies including Genentech, Gilead Sciences, and Oracle.

• Name: San Mateo County California Community College District
• CUSIP: 799038KR4
• Maturity: 9/01/2025
• Coupon: 5%

Located in the San Francisco Bay area with a population of over 260,000. GDP within the county was $18.2 billion in 2016.

• Name: Marin County Certificate of Participation
• CUSIP: 567833EF1
• Maturity: 8/01/2025
• Coupon: 4.7%

Prince William County is another beneficiary of the Washington D.C. economy. Home prices rose 8.8% in 2016.

• Name: Prince William County General Obligation
• CUSIP: 741751X55
• Maturity: 8/01/2024
• Coupon: 5%

Somerset County is located between New York City and Philadelphia and has a diverse labor market with over 166,000 workers employed across many industries.

• Name: Somerset County General Obligation
• CUSIP: 834664S88
• Maturity: 10/01/2023
• Coupon: 3%

Although Calvert County is last on our list, the median household income still comes in at about $99,000, which is more than the majority of counties in the country.

• Name: Calvert County General Obligation
• CUSIP: 131537WL2
• Maturity: 5/01/2026
• Coupon: 3.6%

Many of the richest counties also have some of the highest credit ratings. While further due diligence is always required, beginning your search for bonds with counties with high household incomes tends to be a good indicator of a strong economy and potentially makes a good municipal investment.

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