I've learned a little about how Medicare coverage for Actemra works in California. It it probably similarly elsewhere, but some of what I write below is specialized to Kaiser Permanente Northern California (KPNC), which serves the San Francisco Bay area. Bottom line: for those on Medicare, it looks like by using KPNC's Medicare Part D plan, Actemra injections are covered and are cheaper than the alternative, Actemra infusions. This does not include the effect of support plans that have income testing.

There are two ways to get Actemra:
1) Infusion (administered at a medical center)
2) Self injections.
This matters because these two routes are paid for by different parts of Medicare, with different rates and maximums.

INFUSIONS of Actemra, which are given once a month at a medical center, are considered medical procedures and are therefore covered by Medicare Part B (the medical insurance part for things like doctor visits and outpatient care). There is a 20% copay, which I'm told ends up being about $700-$800/month. If you are at KPNC on Medicare, there are 2 plans. One has a $3900 annual out of pocket maximum, and the other has $6000. So you pay the $700-$800/month for Actemra until you hit the out of pocket maximum. Based solely on this, the plan that has a $3900 out of pocket max is cheaper, even though it has a $70/month premium and the other plan's premium is $0. The total would be $4740 for a year of Actemra. But it turns out injections are less, perhaps much less.

INJECTIONS of Actemra, which are self-administered, typically once a week or every other week, are considered drugs, and are therefore covered by Medicare Part D (the part that covers drugs). There are many suppliers of Medicare Part D, and if you sign up with KPNC for Medicare Part A&B, you can still sign up for Part D elsewhere. However, looking at the US government's Medicare.gov site, it turns out that the KPNC Part D plan is very competitive in benefits, and it does cover Actemra, and further, Part D is includes at no additional cost when you get Part A&B coverage from KPNC. There is an out of pocket maximum for the KPNC Part D plan, which I am told is about $3300 for 2024, and was scheduled to go to $3500 for 2025. However, I am told, due to new government regulations, that the out of pocket maximum is likely to be at most $2000 for 2025, and this will be true for any Part D plan offered anywhere. The details of copays on Kaiser's Part D are complex (initially a 33% copay, followed by $20% once the total drug cost to KPNC has been $5000, so after about 6 weeks for Acterma, then no copay). But you'll never pay more that the out of pocket maximum for the Part D plan, so either $3500 or $2000 for a year of Actemra in 2025, depending on when the government regulations begin to be enforced.

None of the above includes the normal monthly payments for Medicare since you will have to pay those no matter what you do, even if you don't get Actemra. The costs I've stated above are the additional costs to get Actemra.