more doctors refusing to take new or existing Medicare patients than other states.
Fortunately, the most highly rated Medical facilities in the country, including in Texas do not follow that path
A few years back Medicare did increase the reimbursement rate to the primary care physicians, along with others. Still less than other insurers pay, and is also another reason why doctors and facilities pad their Medicare patient bills because they expect one's supplemental plans to cover part or all that Medicare does not cover.
The major medical centers also have contract prices with insurance companies, so even though a bill may indicate a substantial amount, the actual bill may be considerably less
In many cases, the "accept some medicare patients" would refer to those that have a supplemental plan, especially the higher coverage supplementals, such as a Plan F, backed by a large insurance company such as United HealhCare, Blue Cross, Blue Shied, etc, because they will get a larger payment to take care of services not covered by Medicare A&B.
This has also been an increasing trend, more so in certain sections of the country than others. That is why Single Payer is not without its issues, and has the potential for unintended consequences
Here is an interesting perspective on the situation in Canada:
http://www.pnhp.org/news/2008/february/10_myths_about_canad.php