Morning Money Memo…

How much do you know about Obamacare? With less than two months to go before the insurance exchanges offer a series of coverage choices, a new poll finds Americans are confused and doubtful about what's involved.

"We were really surprised that 68 percent of our survey respondents who are uninsured right now and have a pre-existing condition have no idea what they're going to do," says Laura Adams of insurancequotes.com. "Fourteen percent of them said you know what, I'm just going to remain uninsured."

People with diabetes, cancer and other serious health problems stand to benefit the most from the reforms. Until now "they've been priced out of health insurance or have been denied coverage altogether," says Adams. "The Affordable Care Act will allow all consumers to get health care regardless of their health condition."

The survey finds 85 percent of those polled don't think consumers have received enough information about Obamacare. "Many observers are worried that healthy Americans won't sign up for health insurance next year. This research suggests that we should also be worried about unhealthy Americans failing to enroll."

Three local governments in Michigan have pulled planned municipal bond sales off the market since Detroit filed for bankruptcy protection last month. The setbacks are the latest sign that Detroit's filing has shaken up the municipal bond market.

Saginaw County in Michigan withdrew a $61 million sale to cover pension obligations after investors demanded higher rates. Battle Creek delayed a $16 million general obligation bond issue. Detroit's bankruptcy could make it more difficult for many other communities to borrow money. Detroit owes billions to bondholders and billions more in pensions to retired city workers. Many cities and counties face funding questions about how they will pay for public workers' pensions in the years to come.

For the first time in several years T-Mobile is adding wireless subscribers. Apple's iPhone and new pricing plans are helping the company gain customers. Once regarded as an afterthought in the industry, T-Mobile US says it added 688,000 contract customers in the April-June quarter, compared with a loss of 557,000 a year ago. Part of the boost came because the carrier began selling Apple's iPhone for the first time in April. But T-Mobile also credits new pricing plans. In March, T-Mobile dropped its conventional two-year service contracts in favor of selling phones with installment plans.

David Karp has a huge incentive to stay at Tumblr, the blogging service he founded. Yahoo will pay $110 million to Karp if he stays on the job for the next four years. The retention payment has been disclosed in a regulatory filing. California-based Yahoo recently completed its acquisition of Tumbr. Karp turned 27 last month. He started Tumblr in 2007, a few years after he dropped out of high school in New York to concentrate on computer programming. Yahoo CEO Marissa Mayer has pledged not to make any dramatic changes at Tumblr. As part of that promise, Mayer is allowing Karp to run Tumblr independently in New York.

Richard Davies Business Correspondent ABC News Radio abcnews.com Twitter: daviesabc

Note: The Memo will take a brief break and return Thursday of next week, Aug. 15