The American Medical Association, which endorsed the House health care reform bill, has raised “serious concerns— with the mark of Senate Finance Chairman Max Baucus (D-Mont.).

The AMA’s executive vice president and CEO, Michael Maves, sent a letter Monday — the day before the bill is to be marked up — to Baucus attacking several of his bill’s provisions. The AMA doesn’t like a proposal that would establish a $350 fee for doctors to enroll in the Medicare or Medicaid programs. Supporters say the fee would help the government pay to find fraud and abuse in the programs.

“Physicians are already subject to multiple fraud and abuse review processes … and the type of measures being proposed in the mark simply add a new burden on physicians whose reimbursement under Medicare already fails to keep pace with increasing patient costs,— Maves wrote.

The doctors’ lobby also takes issue with Baucus’ framework for reforming the Medicare payment formula. Baucus’ plan would only be a temporary solution, the AMA argues, adding that it supports a permanent fix.

The group’s letter also raises opposition to the proposed structure of the Independent Medicare Commission, which could establish the size of Medicare payments to doctors. The measure could, Maves wrote, “subject physician services to multiple payment cuts in a single year. Further, the provision does not appear to apply equally to all health care stakeholders.—

The doctors group said it likes Baucus’ plan to provide primary care and general surgery bonuses under Medicare to keep more doctors in those fields instead of going into specialties, which often have higher reimbursement rates for doctors. But the AMA doesn’t want the bonuses to be paid for by reductions to other physicians. “We strongly encourage you to identify other pay-fors to fully fund the proposed bonuses that do not make across-the-board cuts to other Medicare physician services,— Maves wrote, noting that, “We support many of the provisions in the mark.—