Please see How do I Prepare a Prior Year Filing? for information on completing your filing prior to using the DFVC program or click here for more detailed prior year filing instructions from the 5500 User Guide.
If you need to complete a schedule for one of your prior years and it is not present from the "Add Schedules" box (as many schedules are not available for years prior to 2002), you will need to download the forms you need from the DOL website, complete the schedules and add these as PDF attachments to your filing. This website does appear to only go back to 1995, so you may need to "Google" whether or not a form/schedule is available for 1994 and prior.
Note: you may also want to review the DOL FAQs for the Delinquent Filer Voluntary Compliance Program (DFVCP) to determine if you have any penalties, etc.
If you need to complete filings for years prior to 1988, we do suggest adding a second plan to the company and selecting the 1988 or 1989 plan years to complete these filings. You may want to slightly alter the plan name within the system to differentiate between the two separate plans.