Those costs are at 2018 rates. A couple both on Medicare will pay double the amount shown. Premiums vary for Part D and for supplemental coverage based on location and plan selected. An individual with an income in retirement of more than $85,000 will pay substantially more for Part B premiums (as will the spouse).
QUINNSCOMMENTARY 
I will guess with the poor savings rate in the USA there are not that many retirees with incomes even close to $85,000 per year. 10 to 20 percent would be my guess. I am at $35K and one sister is at $45K with another sister at $30K. With Zero debt and 12 year old car, retirement can be managed very well.
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In 2016, 49.5 million Americans were age 65 and older. Half of all older adults had less than $23,394 in yearly income from all sources.
In 2016, half of all older households received less than $39,823 in yearly income from all sources.
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