You almost never hear this business mentioned on CNBC, but it has quietly made a small group of people rich.

Each year, the General Services and Administration Department dolls out $21.0 billion to keep the federal government humming. The biggest hole in their budget? Rent. While “Uncle Sam” might own a lot of property, he’s also the nation’s biggest tenant.

Some investors have made a fortune leasing office space to the government. The Feds, after all, usually make the rent. One landlord in particular has earned reliable income in this niche and pays investors a 7.9% yield to boot.

I’m talking about Government Properties Income Trust (GOV). This partnership leases out more than 11-million square feet of office space, mostly to the public sector. And while it gets little coverage in the press, I love the business for a couple of reasons.

Earn a 7.9% Yield From the Government’s Landlord

First, you have the world’s best tenant.

The IRS represents GOV’s largest customer by square feet. The U.S. Department of Citizenship and Immigration takes the next spot. Altogether, Federal and State departments account for 90% of the firm’s rental income.

Needless to say, you have a much more dependable tenant than the nice folks answering a Craigslist ad. The U.S. government is rock solid from a financial perspective. These agencies are not going out of “business” anytime soon.

Government departments also tend to stay put. Nowadays, you’d jump for joy if a tenant signs a one year lease (and actually pays on time). Many agencies, in contrast, sign leases for 20 years or longer, with the option to extend for another five to 10 years.

In other words, GOV’s cash flows resemble bond coupons. Profits, you don’t have to worry about; they always roll in. GOV could check the dates on the calendar that will get paid years ahead of time.

Better still, these leases produce eye-popping profits.