The Centers for Medicare and Medicaid has announced the Medicare premiums, deductibles, and coinsurances for 2015. For the second year in a row, both the standard Medicare Part B premium of $104.90 a month and the Part B deductible of $147 will remain the same. Meanwhile, cost-sharing for hospital and skilled nursing stays will rise slightly.  In a statement, Secretary of the Department of Health & Human Services Sylvia Burwell attributed the stabilization of Part B premiums to cost savings from the Affordable Care Act, aka "Obamacare." 

Here are all the new Medicare figures:

• Part B premium: $104.90/month (unchanged)
• Part B deductible: $147 (unchanged)
• Part A deductible: $1,260 (was $1,216)
• Co-payment for hospital stay days 61-90: $315/day (was $304)
• Co-payment for hospital stay days 91 and beyond: $630/day (was $608)
• Skilled nursing facility co-payment, days 21-100: $157.50/day (was $152)

Higher-income beneficiaries will pay higher Part B premiums. The amounts for 2015 will remain unchanged from 2014 as well:

• Individuals with annual incomes between $85,000 and $107,000 and married couples with annual incomes between $170,000 and $214,000 will pay a monthly premium of $146.90 (unchanged).
• Individuals with annual incomes between $107,000 and $160,000 and married couples with annual incomes between $214,000 and $320,000 will pay a monthly premium of $209.80 (unchanged).
• Individuals with annual incomes between $160,000 and $214,000 and married couples with annual incomes between $320,000 and $428,000 will pay a monthly premium of $272.70 (unchanged).
• Individuals with annual incomes of $214,000 or more and married couples with annual incomes of $428,000 or more will pay a monthly premium of $335.70 (unchanged).

Rates differ for beneficiaries who are married but file a separate tax return from their spouse:

• Those with incomes between $85,000 and $129,000 will pay a monthly premium of $272.70 (unchanged).
• Those with incomes greater than $129,000 will pay a monthly premium of $335.70 (unchanged).

The Social Security Administration uses the income reported two years ago to determine a Part B beneficiary's premiums. So the income reported on a beneficiary's 2013 tax return is used to determine whether the beneficiary must pay a higher monthly Part B premium in 2015. Income is calculated by taking a beneficiary's adjusted gross income and adding back in some normally excluded income, such as tax-exempt interest, U.S. savings bond interest used to pay tuition, and certain income from foreign sources. This is called modified adjusted gross income (MAGI). If a beneficiary's MAGI decreased significantly in the past two years, she may request that information from more recent years be used to calculate the premium.

Those who enroll in Medicare Advantage plans may have different cost-sharing arrangements. On average Medicare Advantage premiums are expected to rise $2.94 a month to $33.90 in 2015. 

For more information on the Medicare figures, click here. 

For Medicare's "Medicare costs at a glance," click here.

For more about Medicare, click here.