Can an employer pay a larger portion of health insurance premiums for some employees and a smaller percentage for other employees. For example, say the employer wishes to pay 100% of management's health insurnace premiums but only 50% of rank and file workers. The premiums are paid directly to the insurance provider. Would the management employees be subject to tax on the premiums paid to insurance company?

The answer would depend on the results of the a/d tests.

Yes, the employer can do this, if there are two legitimate groups set-up by the employer, such as; union/non-union, management/non-management, etc. As for the taxation question, no there would be no tax consequence to the management staff. All contributions by the employer are tax free.

You may have an issue with the carrier, but that is a different story.