26 C.F.R. § 1.1401-1 : Internal Revenue — INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY — INCOME TAX — INCOME TAXES —EMPLOYMENT INCOME —1 - Tax on self-employment income

(a) There is imposed, in addition to other taxes, a tax upon the self-employment income of every individual at the rates prescribed in section 1401(a) (old-age, survivors, and disability insurance) and (b) (hospital insurance). (See subparagraphs (1) and (2) of paragraph (b) of this section.) This tax shall be levied, assessed, and collected as part of the income tax imposed by subtitle A of the Code and, except as otherwise expressly provided, will be included with the tax imposed by section 1 or 3 in computing any deficiency or overpayment and in computing the interest and additions to any deficiency, overpayment, or tax. Since the tax on self-employment income is part of the income tax, it is subject to the jurisdiction of the Tax Court of the United States to the same extent and in the same manner as the other taxes under subtitle A of the Code. Furthermore, with respect to taxable years beginning after December 31, 1966, this tax must be taken into account in computing any estimate of the taxes required to be declared under section 6015.

(b) The rates of tax on self-employment income are as follows (these regulations do not reflect off-Code revisions to the following rates):

(1) For Old-age, Survivors, and Disability Insurance:

Taxable year	Percent
Beginning after December 31, 1983 and before January 1, 1988	11.40
Beginning after December 31, 1987 and before January 1, 1990	12.12
Beginning after December 31, 1989	12.40

(2)

(i) For Hospital Insurance:

Taxable year	Percent
Beginning after December 31, 1983 and before January 1, 1985	2.60
Beginning after December 31, 1984 and before January 1, 1986	2.70
Beginning after December 31, 1985	2.90

(ii) For Additional Medicare Tax:

Taxable year	Percent
Beginning after December 31, 2012	0.9

(c) In general, self-employment income consists of the net earnings derived by an individual (other than a nonresident alien) from a trade or business carried on by him as sole proprietor or by a partnership of which he is a member, including the net earnings of certain employees as set forth in §1.1402(c)-3, and of crew leaders, as defined in section 3121(o) (see such section and the regulations thereunder in part 31 of this chapter (Employment Tax Regulations)). See, however, the exclusions, exceptions, and limitations set forth in §§1.1402(a)-1 through 1.1402(h)-1.

(d) Special rules regarding Additional Medicare Tax.

(1) General rule. An individual is liable for Additional Medicare Tax to the extent that his or her self-employment income exceeds the following threshold amounts.

Filling status	Threshold
Married individual filing a joint return	$250,000
Married individual filing a separate return	125,000
Any other case	200,000

Note: These threshold amounts are specified under section 1401(b)(2)(A).

(2) Coordination with Federal Insurance Contributions Act.

(i) General rule. Under section 1401(b)(2)(B), the applicable threshold specified under section 1401(b)(2)(A) is reduced (but not below zero) by the amount of wages (as defined in section 3121(a)) taken into account in determining Additional Medicare Tax under section 3101(b)(2) with respect to the taxpayer. This rule does not apply to Railroad Retirement Tax Act (RRTA) compensation (as defined in section 3231(e)).

(ii) Examples. The rules provided in paragraph (d)(2)(i) of this section are illustrated by the following examples:

Example 1. A, a single filer, has $130,000 in self-employment income and $0 in wages. A is not liable to pay Additional Medicare Tax.

Example 2. B, a single filer, has $220,000 in self-employment income and $0 in wages. B is liable to pay Additional Medicare Tax on $20,000 ($220,000 in self-employment income minus the threshold of $200,000).

Example 3. C, a single filer, has $145,000 in self-employment income and $130,000 in wages. C's wages are not in excess of $200,000 so C's employer did not withhold Additional Medicare Tax. However, the $130,000 of wages reduces the self-employment income threshold to $70,000 ($200,000 threshold minus the $130,000 of wages). C is liable to pay Additional Medicare Tax on $75,000 of self-employment income ($145,000 in self-employment income minus the reduced threshold of $70,000).

Example 4. E, who is married and files a joint return, has $140,000 in self-employment income. F, E's spouse, has $130,000 in wages. F's wages are not in excess of $200,000 so F's employer did not withhold Additional Medicare Tax. However, the $130,000 of F's wages reduces E's self-employment income threshold to $120,000 ($250,000 threshold minus the $130,000 of wages). E and F are liable to pay Additional Medicare Tax on $20,000 of E's self-employment income ($140,000 in self-employment income minus the reduced threshold of $120,000).

Example 5. D, who is married and files married filing separately, has $150,000 in self-employment income and $200,000 in wages. D's wages are not in excess of $200,000 so D's employer did not withhold Additional Medicare Tax. However, the $200,000 of wages reduces the self-employment income threshold to $0 ($125,000 threshold minus the $200,000 of wages). D is liable to pay Additional Medicare Tax on $75,000 of wages ($200,000 in wages minus the $125,000 threshold for a married filing separately return) and on $150,000 of self-employment income ($150,000 in self-employment income minus the reduced threshold of $0).

(e) Effective/applicability date. Paragraphs (b) and (d) of this section apply to quarters beginning on or after November 29, 2013.

26 C.F.R. §1.1401-1

T.D. 6993, 34 FR 828, 1/18/1969, as amended by T.D. 7333, 39 FR 44445, 12/24/1974; T.D. 9645, 78 FR 71471, 11/29/2013