The Senate committee in charge of financing the upcoming healthcare overhaul is considering changes that could place new financial burdens on Massachusetts institutions and employees, including limiting the tax exclusion for employer-provided health coverage, a major benefit to employees in states like Massachusetts, where insurance is expensive and plans tend to be generous. ... The policy options would either tinker with Medicare payments in hopes of wringing waste and inefficiency out of the system, or would limit healthcare-related tax benefits, such as health savings accounts. The document also proposed new tax rules that could affect major Massachusetts institutions, including requiring...