Adds a deeming clause to the definition of "employer" (section 3(5)) to specify that, for purposes of offering a group health plan or group health insurance coverage, the term includes any entity that meets the requirements under new section 736(b) (including entities offering prescription or nonprescription drugs as the only benefit).

Makes conforming and clarifying amendments to Section 3 of ERISA: (1) inserts text before the period in paragraph (6) (text of insertion not provided in this section); (2) modifies paragraph (21) by updating a cross-reference in subparagraph (A) (striking "subparagraph (B)" and inserting "subparagraphs (B) and (C)") and by adding a new subparagraph (C) clarifying that membership in a health marketplace pool that meets section 736(b) and offers group health plans/coverage does not by itself make a person a fiduciary with respect to such plan or coverage; and (3) amends paragraph (40)(A) by adding a new clause (iv) to include as a group health plan or group health insurance coverage a plan offered by an entity meeting section 736(b).

Adds a new section (designated "736") to Part 7 of subtitle B of title I of ERISA establishing "health marketplace pools." The new section deems entities meeting the section's requirements to be "employers" for purposes of offering group health plans or group health insurance coverage, and sets out detailed requirements and rules for such health marketplace pools (organization and membership rules, nondiscrimination and enrollment rules, permissible methods of providing coverage including contracting with issuers or self-insurance, allowance for drug-only coverage including over-the-counter drugs, administrative services, geographic scope language permitting multiple pools, rules on determination of employer and joint-employer status, and a definition of "dependent" as applied under State law).

Makes multiple amendments to section 223 (Health savings accounts): replaces paragraph (1) limitation formula with an amount equal to the applicable dollar amount under section 402(g)(1)(B) (as adjusted); inserts a new additional-contribution rule for individuals who have attained age 50 referencing section 414(v)(2)(B)(i) (as adjusted); strikes paragraphs (2), (3), (5), (7), and (8); redesignates paragraphs; removes certain subsections and redesignates others; adds provisions treating certain pre-establishment medical expenses as qualified, creates an exception for administrative errors corrected before the return due date, allows specified rollovers to a child (and related conforming language), and adds 'qualified wellness expenses' (including vitamins, dietary supplements as defined in 21 U.S.C. 321(ff), gym memberships, and wearable fitness trackers); and makes numerous conforming amendments to other Code sections to reflect the redesignations.

Makes conforming and substantive amendments to section 106: updates cross-references to redesigned subsections of section 223 (e.g., replacing references to 'section 223(d)' with 'section 223(c)'); strikes and redesignates certain paragraphs in subsection (e), inserts a new paragraph treating a qualified HSA distribution as a rollover described in section 223(e)(4), and modifies wording in a paragraph to reference employees 'with respect to whom a health savings account has been established.'

Technical amendment to section 220(d)(2)(A): replaces the cross-reference 'section 223(d)(2)(D)' with 'section 223(c)(2)(B)'.

Adds a new subsection (r) to section 522 providing that, for purposes of that section, any health savings account (as described in section 223 of the Internal Revenue Code) shall be treated in the same manner as an individual retirement account described in section 408 of the Internal Revenue Code.