In 2013, the standard Medicare Part B premium was $104.90 per month for most people. However, for some beneficiaries, the premium was higher due to income-related adjustments. Additionally, the Medicare Part A premium for those who had to buy it was up to $441 per month in 2013. It's important to note that these figures are for 2013 and may not reflect current costs or premiums. The standard Medicare Part B premium in 2013 was $104.90 per month. For some beneficiaries, the premium was higher due to income-related adjustments. The Medicare Part A premium for those who had to buy it was up to $441 per month in 2013.