costs for hospital care but be more expensive for seniors who mostly use Part B. In addition, some proposals suggest a 10 to 20 percent co-payment for all services until beneficiaries reach a catastrophic limit of $7,500. Others argue for making that $550 deductible ineligible for Medigap coverage so that beneficiaries are responsible for covering the cost of those initial services. Instituting the change in deductibles, co-pays and Medigap rules would save about $93 billion over the next decade, CBO estimates . Medicare would save money, but not just because beneficiaries were putting up more of their own. If Medigap plans were less generous, analysts believe beneficiaries would be more careful about spending and that could help lower Medicare costs. Expect insurers that sell Medigap policies -- especially those that offer first-dollar coverage -- to balk.