I just realized I forgot to attach Schedule B to my 2015 Form 1040 that I filed in April. What should I do now?

High deductible health plan (HDHP)

For 2007, a high deductible health plan is a health plan with an annual deductible that is not less than $1,100 for self-only coverage or $2,200 for family coverage, and with annual out-of-pocket expenses that do not exceed $5,600 or $11,200, respectively.