The first deduction holiday for 2017 is already here. Because deductions for health & welfare occur 4 times per month, months with 5 pay periods produce a "deduction holiday". December 2016 had 5 Saturdays, so the first deduction holiday of 2017 will be Jan 10th. Because of open enrollment changes a higher number than usual are in "catch-up" status. See link below to FAQ - health & welfare deductions - for more details.
When you or your spouse becomes eligible for Medicare, you should enroll in Medicare Parts A and B. For most people, enrollment in Medicare Part A is automatic (there is no premium) when you start receiving benefits from Social Security. You should sign up for Medicare Part B with the Social Security office three months before turning 65. Your monthly premium to Medicare for Part B will be deducted from your Social Security check.
When you become eligible, you are not required to enroll in Medicare Part B, but benefits will be paid by the Plan as if you are enrolled. This means that, if you do not enroll, you or your spouse will have higher expenses because you will be responsible for paying for the benefits Medicare Part B would have covered. After you submit evidence of your Part B enrollment for yourself or your dependent, your HEALTH & WELFARE Plan premium will be reduced. For more information, visit the "If You Become Eligible for Medicare" section on the Life Events page.