The new Tax Cut and Jobs Act law passed in 2017 modified the deductions businesses can take.  These are the changes.
Child Tax Credit

The child tax credit was increased from $1,000 to $2,000.  The first $1,400.  The phaseout threshold will  dramatically increase from $110,000 to $400,000 for married filers.

 
The Alternative Minimum Tax (AMT) for Individuals:
Raises the exemption on the alternative minimum tax from $86,200 to $109,400 for married filers, half this amount for married taxpayers filing a separate return), and $70,300 for all other taxpayers (other than estates and trusts). The phaseout thresholds are increased to $1,000,000 for married taxpayers filing a joint return, and $500,000 for all other taxpayers (other than estates and trusts).
Estate Tax:
Raises the estate tax exemption to $5,400,000.  A 40% tax is imposed on any amount about that.
Individual Mandate

Effective 1 January 2019 the individual mandate for the Affordable Care Act (ACA) is repealed.

 
Personal Deductions Kept

-Charitable Deduction

-State and Local Tax Deduction is limited to $10,000(sales tax, state income tax & property tax).  Taxes paid or accrued in carrying on a trade or business are not limited.

-Mortgage Interest Deduction on the first $750,000 on the value of a home

-The limit for the deduction of certain expenses of eligible educators, in determining adjusted gross income, is set to $500.

-Qualified bicycle commuting reimbursements of up to $20 per qualifying bicycle commuting month are excludible from an employee’s gross income.

 
Personal Deductions Eliminated

-Appraisal fees for a casualty loss or charitable contribution;

-Casualty and theft losses from property used in performing services as an employee;

-Clerical help and office rent in caring for investments;

-Depreciation on home computers used for investments;

-Excess deductions (including administrative expenses) allowed a beneficiary on termination of an estate or trust;

-Fees to collect interest and dividends;

-Hobby expenses, but generally not more than hobby income;

-Indirect miscellaneous deductions from pass-through entities;

-Investment fees and expenses;

-Loss on deposits in an insolvent or bankrupt financial institution;

-Loss on traditional IRAs or Roth IRAs, when all amounts have been distributed;

-Repayments of income;

-Safe deposit box rental fees, except for storing jewelry and other personal effects;

-Service charges on dividend reinvestment plans; and

-Trustee’s fees for an IRA, if separately billed and paid.

-Medical Expenses

-Deductions for personal exemptions

-Deduction for alimony payments and corresponding inclusion in gross income.

-Deduction for moving expenses

-Deduction and exclusions for contributions to medical savings accounts.

-Deduction for performing artists and certain officials.