There have been many articles and papers written on the importance of the financial ratings for long term care insurance companies. One of the reasons this is so important is that there has not been a very long history with this type of insurance from an actuary stand point. For example companies have been writing life insurance policies for 100 years. Thus they have a tremendous amount of data to analyze which helps them come up with accurate figures on what they must charge in order to take in enough funds to cover all pay outs.
With LTC insurance this is not the case. Most of the people who have bought policies have in fact never activated them. As people live longer now, they will most likely require more care than people did 50 years ago.
The financial health of a carrier is very important. Here is a discussion thread on the financial ratings of insurance companies.