Yes any years that need correction need to be filed with an amended return.
About Form 8606, Nondeductible IRAs states:
Amending Form 8606
Generally, after you file your return, you can change a nondeductible contribution to a traditional IRA to a deductible contribution or vice versa if you make the change within the time limit for filing Form 1040-X, Amended U.S. Individual Income Tax Return (see When To File in the Form 1040-X instructions). You also may be able to make a recharacterization (discussed earlier). If necessary, complete a new Form 8606 showing the revised information and file it with Form 1040-X.
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