Doctors and seniors are urging Congress to block a massive Medicare rate reduction that they fear would cause some physicians to drop patients or close their practices. Yesterday, U.S. Senate leaders indicated that they had a tentative deal to freeze Medicare payments to physicians for one year to avoid a scheduled 25% rate cut starting Jan. 1. The agreement could be brought up for approval as early as today. Sound familiar? It should. This will be the fifth "doc fix" Congress has approved this year; the most recent agreement lasted only a month.