I can only guess that since Plan J was discontinued from being sold in 2010 that there are few beneficiaries still around to use it. But the ones that are maybe really really using it. She may have gone from an area (around Chicago) that had several still on the plan since it may have been more populated to an area where there are only a few who remain on this plan.

It isn't so much about health care cost with a Medigap policy because it isn't really health insurance, it is financial protection insurance linked to Traditional Medicare to cover some or all of the beneficiary's out of pocket cost and it prevents a financial catastrophe due to medical cost as long as one stays within the Medicare system of providers. Medigap policies do increase with usage cost (the cost of everybody's usage) and medical inflation and the whatever rating method they used with the policy - community rated, attained age or issue age.

It's now and has been acting like a closed book policy - IOW, no new younger people are being let in to the plan to balance out the ones that are getting older and sometimes sicker. So without this type of offset, you might be dealing with the few that are still on Plan J who are really, really having to use it - so up goes the premium.

Since CMS closed the marketing of this plan back in 2010 because it was at the time the richest plan in benefits, then everybody that still has a Plan J has to be getting on up there in age. My mother had one too but she died in 2015 at the age of 90 and at that time her premiums were almost $ 400 a month.

I checked to see if Nebraska was a state that had expanded some of the guaranteed rules but it does not appear that they are so in order for her to change to another policy she would have to go thru underwriting and then if she has some pre-existing conditions, they could uprate her and charge even more in premiums or not cover any preexisting condition for a period of time - like 6-months.

You can contact the SHIP counselors in Nebraska and talk to them about it - That's the State Health Insurance Plan Assistance - usually under the state Dept of Ins.

Here is a link and their contact info is on the last page.

It may be that this is the rate - it isn't a good idea to stay with a "dead" plan for too long after CMS has removed it from being purchased. Premiums just go up and the longer one waits the higher they will go.

Maybe the Nebraska Medicare assistants will have some ideas. I just don't see any. Sorry - If nothing else, she could change to a Medicare Advantage plan but make sure it is a high rated plan with at least PPO coverage and the providers your mom wants to see. That's just an option if nothing else can be done . Again, Sorry.