2018 inflation-adjusted figures for contributions to HSAs have been released by the IRS.

Annual limitations under a high deductible health plan are as follows:
Individual with self-only coverage: $3,450
Individual with family coverage: $6,900

A "high deductible health plan" is defined as a plan with an annual deductible of not less than $1,350 for self-only coverage or not less than $2,700 for family coverage, and where annual out-of-pocket expenses don't exceed $6,650 (self-only) or $13,300 (family coverage).