Osteoporosis Early Detection and Prevention Act of 2005 - Amends the Public Health Service Act and the Employee Retirement Income Security Act of 1974 (ERISA) to require a group health plan, and an insurer offering group coverage, to include coverage for bone mass measurement for individuals who: (1) are at a clinical risk for osteoporosis, including estrogen-deficient women; (2) have vertebral abnormalities; (3) are receiving chemotherapy or long-term gluococorticoid (steroid) therapy; (4) have primary hyperparathyroidism, hyperthyroidism, or excess thyroid replacement; or (5) are being monitored to assess the response to or efficacy of approved osteoporosis drug therapy. Allows the Secretary of Health and Human Services to regulate the frequency with which individuals will be provided this benefit. Permits cost sharing, including deductibles and coinsurance. Prohibits specified actions discouraging the use of this benefit, including: (1) denying coverage; (2) offering incentives to not obtain or provide bone mass measurements; (3) restricting provider-patient communications; and (4) penalizing or limiting reimbursements to providers. Allows state laws providing greater detection or prevention benefits. Amends the Public Health Service Act to apply these requirements to coverage offered in the individual market.