src/fed2019/Form1040.ts

   1 import { Form, TaxReturn } from '../core';
   2 import { Line, AccumulatorLine, ComputedLine, ReferenceLine, sumLineOfForms } from '../core/Line';
   3 import { UnsupportedFeatureError } from '../core/Errors';
   4 import { clampToZero, reduceBySum } from '../core/Math';
   5
   6 import Form8606 from './Form8606';
   7 import Form8959 from './Form8959';
   8 import Form1099INT from './Form1099INT';
   9 import Form1099DIV from './Form1099DIV';
  10 import Form1099R, { Box7Code } from './Form1099R';
  11 import W2 from './W2';
  12 import Schedule1 from './Schedule1';
  13 import Schedule2 from './Schedule2';
  14 import Schedule3 from './Schedule3';
  15 import ScheduleD, { ScheduleDTaxWorksheet } from './ScheduleD';
  16
  17 export enum FilingStatus {
  18   Single = 'S',
  19   MarriedFilingSeparate = 'MFS',
  20   MarriedFilingJoint = 'MFJ',
  21 };
  22
  23 export interface Form1040Input {
  24   filingStatus: FilingStatus;
  25 };
  26
  27 export default class Form1040 extends Form<Form1040['_lines'], Form1040Input> {
  28   readonly name = '1040';
  29
  30   protected readonly _lines = {
  31     '1': new AccumulatorLine(W2, '1', 'Wages, salaries, tips, etc.'),
  32     '2a': new AccumulatorLine(Form1099INT, '8', 'Tax-exempt interest'),
  33     '2b': new AccumulatorLine(Form1099INT, '1', 'Taxable interest'),
  34     '3a': new AccumulatorLine(Form1099DIV, '1b', 'Qualified dividends'),
  35     '3b': new AccumulatorLine(Form1099DIV, '1a', 'Ordinary dividends'),
  36     '4a': new ComputedLine((tr): number => {
  37       const f1099Rs = tr.findForms(Form1099R).filter(f => !f.getValue(tr, '7').includes(Box7Code.G));
  38       return sumLineOfForms(tr, f1099Rs, '1');
  39     }),
  40     '4b': new ComputedLine((tr): number => {
  41       const f8606s = tr.findForms(Form8606);
  42       return sumLineOfForms(tr, f8606s, '15c') + sumLineOfForms(tr, f8606s, '18');
  43     }, 'IRA distributions, taxadble amount'),
  44     '4d': new ComputedLine(() => 0),
  45     // 4c and 4d are not supported
  46     // 5a and 5b are not supported
  47     '6': new ComputedLine((tr): number => {
  48       const schedD = tr.findForm(ScheduleD);
  49       if (!schedD)
  50         return 0;
  51
  52       const l6 = schedD.getValue(tr, '16');
  53       if (l6 > 0)
  54         return l6;
  55       return schedD.getValue(tr, '21');
  56     }, 'Capital gain/loss'),
  57     '7a': new ReferenceLine(Schedule1, '9', 'Other income from Schedule 1', 0),
  58
  59     '7b': new ComputedLine((tr): number => {
  60       let income = 0;
  61       income += this.getValue(tr, '1');
  62       income += this.getValue(tr, '2b');
  63       income += this.getValue(tr, '3b');
  64       income += this.getValue(tr, '4b');
  65       income += this.getValue(tr, '4d');
  66       //income += this.getValue(tr, '5b');
  67       income += this.getValue(tr, '6');
  68       income += this.getValue(tr, '7a');
  69       return income;
  70     }, 'Total income'),
  71
  72     '8a': new ReferenceLine(Schedule1, '22', 'Adjustments to income', 0),
  73
  74     '8b': new ComputedLine((tr): number => {
  75       return this.getValue(tr, '7b') - this.getValue(tr, '8a');
  76     }, 'Adjusted gross income'),
  77
  78     '9': new ComputedLine((): number => {
  79       // TODO - Itemized deductions.
  80       switch (this.filingStatus) {
  81         case FilingStatus.Single:
  82         case FilingStatus.MarriedFilingSeparate:
  83           return 12200;
  84         case FilingStatus.MarriedFilingJoint:
  85           return 24400;
  86       }
  87     }, 'Deduction'),
  88
  89     '10': new ComputedLine((tr): number => {
  90       const taxableIncome = this.getValue(tr, '8b');
  91       let use8995a = false;
  92       switch (this.filingStatus) {
  93         case FilingStatus.Single:                use8995a = taxableIncome <= 160700; break;
  94         case FilingStatus.MarriedFilingSeparate: use8995a = taxableIncome <= 160725; break;
  95         case FilingStatus.MarriedFilingJoint:    use8995a = taxableIncome <= 321400; break;
  96       };
  97       return 0;
  98     }, 'Qualified business income deduction'),
  99
 100     '11a': new ComputedLine((tr): number => {
 101       return this.getValue(tr, '9') + this.getValue(tr, '10');
 102     }),
 103     '11b': new ComputedLine((tr): number => {
 104       return clampToZero(this.getValue(tr, '8b') - this.getValue(tr, '11a'));
 105     }, 'Taxable income'),
 106
 107     '12a': new ComputedLine((tr): number => {
 108       // Not supported:
 109       // Form 8814 (election to report child's interest or dividends)
 110       // Form 4972 (relating to lump-sum distributions)
 111       const taxableIncome = this.getValue(tr, '11b');
 112
 113       if (this.getValue(tr, '3a') > 0 && !tr.findForm(ScheduleD))
 114         throw new UnsupportedFeatureError('Qualified Dividends and Captial Gains Tax Worksheet not supported, Schedule D requried');
 115
 116       const schedD = tr.findForm(ScheduleDTaxWorksheet);
 117       if (schedD)
 118         return schedD.getValue(tr, '47');
 119
 120       return computeTax(taxableIncome, this.filingStatus);
 121     }, 'Tax'),
 122
 123     '12b': new ComputedLine((tr): number => {
 124       return this.getValue(tr, '12a') + tr.getForm(Schedule2).getValue(tr, '3');
 125     }, 'Additional tax'),
 126
 127     // Not supported: 13a - child tax credit
 128
 129     '13b': new ReferenceLine(Schedule3, '7', 'Additional credits', 0),
 130
 131     '14': new ComputedLine((tr): number => {
 132       return clampToZero(this.getValue(tr, '12b') - this.getValue(tr, '13b'));
 133     }),
 134
 135     '15': new ReferenceLine(Schedule2, '10', undefined, 0),
 136
 137     '16': new ComputedLine((tr): number => {
 138       return this.getValue(tr, '14') + this.getValue(tr, '15');
 139     }, 'Total tax'),
 140
 141     '17': new ComputedLine((tr): number => {
 142       const fedTaxWithheldBoxes = [
 143         new AccumulatorLine(W2, '2'),
 144         new AccumulatorLine(Form1099R, '4'),
 145         new AccumulatorLine(Form1099DIV, '4'),
 146         new AccumulatorLine(Form1099INT, '4'),
 147       ];
 148       const withholding: number[] = fedTaxWithheldBoxes.map(b => b.value(tr));
 149
 150       let additionalMedicare = 0;
 151       const f8959 = tr.findForm(Form8959)
 152       if (f8959) {
 153         additionalMedicare = f8959.getValue(tr, '24');
 154       }
 155
 156       return reduceBySum(withholding) + additionalMedicare;
 157     }, 'Federal income tax withheld'),
 158
 159     // 18a not supported - Earned income credit (EIC)
 160     // 18b not supported - Additional child tax credit. Attach Schedule 8812
 161     // 18c not supported - American opportunity credit from Form 8863, line 8
 162     '18d': new ReferenceLine(Schedule3, '14', undefined, 0),
 163     '18e': new ComputedLine((tr): number => {
 164       // Should include 18a-18c.
 165       return this.getValue(tr, '18d');
 166     }),
 167
 168     '19': new ComputedLine((tr): number => {
 169       return this.getValue(tr, '17') + this.getValue(tr, '18e');
 170     }, 'Total payments'),
 171
 172     '20': new ComputedLine((tr): number => {
 173       return clampToZero(this.getValue(tr, '19') - this.getValue(tr, '16'));
 174     }, 'Amount overpaid'),
 175
 176     '23': new ComputedLine((tr): number => {
 177       return clampToZero(this.getValue(tr, '16') - this.getValue(tr, '19'));
 178     }, 'Amount you owe'),
 179   }
 180
 181   get filingStatus(): FilingStatus {
 182     return this.getInput('filingStatus');
 183   }
 184 };
 185
 186 export function computeTax(income: number, filingStatus: FilingStatus): number {
 187   // From https://www.irs.gov/pub/irs-drop/rp-18-57.pdf, Section 3.01 and
 188   // https://www.irs.gov/pub/irs-pdf/p17.pdf, 2019 Tax Rate Schedules (p254).
 189   const taxBrackets = {
 190     // Format is:
 191     // [ limit-of-taxable-income, marginal-rate, base-tax ]
 192     // If Income is over Row[0], pay Row[2] + (Row[1] * (Income - PreviousRow[0]))
 193     [FilingStatus.MarriedFilingJoint]: [
 194       [ 19400, 0.10, 0 ],
 195       [ 78950, 0.12, 1940 ],
 196       [ 168400, 0.22, 9086 ],
 197       [ 321450, 0.24, 28765 ],
 198       [ 408200, 0.32, 65497 ],
 199       [ 612350, 0.35, 93257 ],
 200       [ Infinity, 0.37, 164709.50 ]
 201     ],
 202     [FilingStatus.Single]: [
 203       [ 9700, 0.10, 0 ],
 204       [ 39475, 0.12, 970 ],
 205       [ 84200, 0.22, 4543 ],
 206       [ 160725, 0.24, 14382.50 ],
 207       [ 204100, 0.32, 32748.50 ],
 208       [ 510300, 0.35, 46628.50 ],
 209       [ Infinity, 0.37, 153798.50 ]
 210     ],
 211     [FilingStatus.MarriedFilingSeparate]: [
 212       [ 9700, 0.10, 0 ],
 213       [ 39475, 0.12, 970 ],
 214       [ 84200, 0.22, 4543 ],
 215       [ 160725, 0.24, 14382.50 ],
 216       [ 204100, 0.32, 32748.50 ],
 217       [ 306175, 0.35, 46628.50 ],
 218       [ Infinity, 0.37, 82354.75 ]
 219     ]
 220   }[filingStatus];
 221
 222   let i = 0;
 223   while (taxBrackets[i][0] < income)
 224     ++i;
 225
 226   const bracket = taxBrackets[i];
 227   const bracketStart = i == 0 ? 0 : taxBrackets[i - 1][0];
 228
 229   return ((income - bracketStart) * bracket[1]) + bracket[2];
 230 };