26 U.S. Code § 223 - Health savings accounts
In the case of an individual who is an eligible individual for any month during the taxable year, there shall be allowed as a deduction for the taxable year an amount equal to the aggregate amount paid in cash during such taxable year by or on behalf of such individual to a health savings account of such individual.
The amount allowable as a deduction under subsection (a) to an individual for the taxable year shall not exceed the sum of the monthly limitations for months during such taxable year that the individual is an eligible individual.
In the case of an individual who has attained age 55 before the close of the taxable year, the applicable limitation under subparagraphs (A) and (B) of paragraph (2) shall be increased by the additional contribution amount.
For purposes of this section, the additional contribution amount is the amount determined in accordance with the following table:
For taxable years beginning in:
The additional contribution amount is:
2009 and thereafter
No deduction shall be allowed under this section to any individual with respect to whom a deduction under section 151 is allowable to another taxpayer for a taxable year beginning in the calendar year in which such individual’s taxable year begins.
The limitation under this subsection for any month with respect to an individual shall be zero for the first month such individual is entitled to benefits under title XVIII of the Social Security Act and for each month thereafter.
Subclauses (I) and (II) of clause (i) shall not apply if the individual ceased to be an eligible individual by reason of the death of the individual or the individual becoming disabled (within the meaning of section 72(m)(7)).
An individual shall not fail to be treated as an eligible individual for any period merely because the individual receives hospital care or medical services under any law administered by the Secretary of Veterans Affairs for a service-connected disability (within the meaning of section 101(16) of title 38, United States Code).
Such term does not include a health plan if substantially all of its coverage is coverage described in paragraph (1)(B).
A plan shall not fail to be treated as a high deductible health plan by reason of failing to have a deductible for preventive care (within the meaning of section 1871 of the Social Security Act, except as otherwise provided by the Secretary).
Such plan shall not fail to be treated as a high deductible health plan by reason of having an out-of-pocket limitation for services provided outside of such network which exceeds the applicable limitation under subparagraph (A)(ii).
The term “qualified medical expenses” means, with respect to an account beneficiary, amounts paid by such beneficiary for medical care (as defined in section 213(d)  for such individual, the spouse of such individual, and any dependent (as defined in section 152, determined without regard to subsections (b)(1), (b)(2), and (d)(1)(B) thereof) of such individual, but only to the extent such amounts are not compensated for by insurance or otherwise. Such term shall include an amount paid for medicine or a drug only if such medicine or drug is a prescribed drug (determined without regard to whether such drug is available without a prescription) or is insulin.
Subparagraph (A) shall not apply to any payment for insurance.
The term “account beneficiary” means the individual on whose behalf the health savings account was established.
A health savings account is exempt from taxation under this subtitle unless such account has ceased to be a health savings account. Notwithstanding the preceding sentence, any such account is subject to the taxes imposed by section 511 (relating to imposition of tax on unrelated business income of charitable, etc. organizations).
Any amount paid or distributed out of a health savings account which is used exclusively to pay qualified medical expenses of any account beneficiary shall not be includible in gross income.
Any amount paid or distributed out of a health savings account which is not used exclusively to pay the qualified medical expenses of the account beneficiary shall be included in the gross income of such beneficiary.
The tax imposed by this chapter on the account beneficiary for any taxable year in which there is a payment or distribution from a health savings account of such beneficiary which is includible in gross income under paragraph (2) shall be increased by 20 percent of the amount which is so includible.
Subparagraph (A) shall not apply if the payment or distribution is made after the account beneficiary becomes disabled within the meaning of section 72(m)(7) or dies.
Paragraph (2) shall not apply to any amount paid or distributed from a health savings account to the account beneficiary to the extent the amount received is paid into a health savings account for the benefit of such beneficiary not later than the 60th day after the day on which the beneficiary receives the payment or distribution.
This paragraph shall not apply to any amount described in subparagraph (A) received by an individual from a health savings account if, at any time during the 1-year period ending on the day of such receipt, such individual received any other amount described in subparagraph (A) from a health savings account which was not includible in the individual’s gross income because of the application of this paragraph.
For purposes of determining the amount of the deduction under section 213, any payment or distribution out of a health savings account for qualified medical expenses shall not be treated as an expense paid for medical care.
The transfer of an individual’s interest in a health savings account to an individual’s spouse or former spouse under a divorce or separation instrument described in subparagraph (A) of section 71(b)(2) shall not be considered a taxable transfer made by such individual notwithstanding any other provision of this subtitle, and such interest shall, after such transfer, be treated as a health savings account with respect to which such spouse is the account beneficiary.
If the account beneficiary’s surviving spouse acquires such beneficiary’s interest in a health savings account by reason of being the designated beneficiary of such account at the death of the account beneficiary, such health savings account shall be treated as if the spouse were the account beneficiary.
The amount includible in gross income under clause (i) by any person (other than the estate) shall be reduced by the amount of qualified medical expenses which were incurred by the decedent before the date of the decedent’s death and paid by such person within 1 year after such date.
 So in original. Probably should be followed by a second closing parenthesis.
For inflation adjustment of certain items in this section, see Revenue Procedures listed in a table below and under section 1 of this title.
The Social Security Act, referred to in subsecs. (b)(7), (c)(2)(C), (d)(2)(C)(iv), (f)(4)(C), is act Aug. 14, 1935, ch. 531, 49 Stat. 620, as amended. Title XVIII of the Act is classified generally to subchapter XVIII (§ 1395 et seq.) of chapter 7 of Title 42, The Public Health and Welfare. Sections 1811, 1871, and 1882 of the Act are classified to sections 1395c, 1395hh, and 1395ss, respectively, of Title 42. For complete classification of this Act to the Code, see section 1305 of Title 42 and Tables.
A prior section 223 was renumbered section 224 of this title.
2015—Subsec. (c)(1)(C). Pub. L. 114–41 added subpar. (C).
2010—Subsec. (d)(2)(A). Pub. L. 111–148, § 9003(a), inserted at end “Such term shall include an amount paid for medicine or a drug only if such medicine or drug is a prescribed drug (determined without regard to whether such drug is available without a prescription) or is insulin.”
Subsec. (f)(4)(A). Pub. L. 111–148, § 9004(a), substituted “20 percent” for “10 percent”.
2006—Subsec. (b)(2)(A). Pub. L. 109–432, § 303(a)(1), substituted “$2,250.” for “the lesser of—
“(i) the annual deductible under such coverage, or
“(ii) $2,250, or”.
Subsec. (b)(2)(B). Pub. L. 109–432, § 303(a)(2), substituted “$4,500.” for “the lesser of—
“(i) the annual deductible under such coverage, or
Subsec. (b)(4)(C). Pub. L. 109–432, § 307(b), added subpar. (C).
Subsec. (b)(8). Pub. L. 109–432, § 305(a), added par. (8).
Subsec. (c)(1)(B)(iii). Pub. L. 109–432, § 302(b), added cl. (iii).
Subsec. (d)(1)(A)(ii)(I). Pub. L. 109–432, § 303(b), substituted “subsection (b)(2)(B)” for “subsection (b)(2)(B)(ii)”.
Subsec. (g)(1). Pub. L. 109–432, § 304, inserted concluding provisions.
2005—Subsec. (d)(2)(A). Pub. L. 109–135 inserted “, determined without regard to subsections (b)(1), (b)(2), and (d)(1)(B) thereof” after “section 152”.
Amendment by section 9003(a) of Pub. L. 111–148 applicable to amounts paid with respect to taxable years beginning after Dec. 31, 2010, see section 9003(d)(1) of Pub. L. 111–148, set out as a note under section 220 of this title.
Amendment by Pub. L. 109–135 effective as if included in the provisions of the Working Families Tax Relief Act of 2004, Pub. L. 108–311, to which such amendment relates, see section 404(d) of Pub. L. 109–135, set out as a note under section 21 of this title.
Provisions relating to inflation adjustment of items in this section for certain years were contained in the following:
2015—Revenue Procedure 2014–30.
2014—Revenue Procedure 2013–25.
2013—Revenue Procedure 2012–26.
2012—Revenue Procedure 2011–32.
2011—Revenue Procedure 2010–22.
2010—Revenue Procedure 2009–29.
2009—Revenue Procedure 2008–29.
2008—Revenue Procedure 2007–36.