One Step Diagnostic – Bay Colony Address Street:2401 Fm 646 Rd W, #B City: Dickinson State:Texas Zip Code:77539 Contact Phone: 832-780-5926 Fax:281-534-2842 Website: www.onestepdiagnostic.com Map & Directions 2401 Fm 646 Rd W, #B, Get Help!If you have been injured, please complete this form to have an office contact you. Notice: JavaScript is required for this content.