Group Health Plan Coverage Expansion Act of 2003

Group Health Plan Coverage Expansion Act of 2003 - Amends the Employee Retirement Income Security Act of 1974 (ERISA) to direct the Secretary of Labor to establish a program to promote and facilitate expansion of coverage under group health plans.

Requires administrators of employee benefit plans under ERISA to notify plan participants, in plan descriptions, of the availability of : (1) child health insurance assistance, through the State Children's Health Insurance Program (SCHIP) under title XXI of the Social Security Act (SSA); and (2) cash benefits for eligible elderly or disabled individuals, through Supplemental Security Income (SSI) payments under title XVI of SSA.

Prohibits group health plans, and health insurance issuers offering group health insurance coverage, under ERISA, from imposing: (1) any aggregate lifetime limit on benefits, including any category of benefits; or (2) any change in the premium rates charged to any participant or beneficiary to make them more than those charged to otherwise similarly situated individuals solely on the basis of a pre-existing condition.

Amends the Internal Revenue Code to allow pension or annuity plans to make payments for premiums for continuation coverage (COBRA benefits, in reference to requirements of title X of the Consolidated Omnibus Budget Reconciliation Act of 1985) under a group health plan on behalf of a qualified beneficiary, if such COBRA benefits are subordinate to retirement benefits provided by the plan and to the qualified current retiree health liabilities of a health benefits account which is part of such plan.

Amends ERISA to authorize the Secretary or a State to bring a civil action for equitable relief against a qualified individual for not maintaining substantial health insurance coverage while obtaining emergency room services. Authorizes a court to order such a defendant to maintain at least two years of substantial health insurance coverage on the patient involved.