Probably within 3 months of when your new coverage starts.
Medicare Advantage plans change each year, and depending on the estimated cost for each Medicare plan member, some also rebate all or a portion of your Medicare Part B premium ($134 in 2018
) back to you as part of your monthly Social Security check.
Please read the Medicare plan coverage details carefully as some plans found in the same area (or county) may not rebate any portion of the Medicare Part B premiums or rebate only a portion of the monthly Medicare Part B premium.
So for instance, if you enroll in the 2018 WellCare Dividend (HMO)
(available to residents of Brevard county, Florida), you will receive a $50 rebate toward your Medicare Part B premium. You may find that the same named Medicare Advantage plan in another county will rebate a higher Medicare Part B premium amount or offer no Part B premium rebate at all.
At any rate, due to the processing time needed when you first enroll into such a Medicare Advantage plan, it may take up to 3-months before you see the rebates or refunds in your Social Security check.
If there is a delay in your monthly rebate payment, you will see that three-months (or whatever time has elapsed) of Medicare Part B premiums will be included at one time in your Social Security check. For example, let's say you enrolled in the 2018 WellCare Dividend (HMO)
and after paying your Medicare Part B premiums in January, February, and March, you would see a total of $150 (or 3 * $50) returned in your Social Security check.
After the first Medicare Part B premium rebate payment, then your monthly Social Security checks should then show a regular increase reflecting the monthly Medicare Part B premium ($134 in 2018 or whatever premium or portion of premium you paid in that year).