Is a $3500 deductible considered a high deductible health plan

You need to contact your insurance carrier to see if your plan qualifies as a High Deductible Health Plan under IRS.

There is more to being an HDHP than just the amount of the deductible. Please don't try to figure this out for yourself, but ask your insurance carrier - your insurance company will certainly know if your plan meets the IRS' requirements for an HDHP.

see this link:

https://www.healthcare.gov/glossary/high-deductible-health-plan/