Retirement tax questions

Does this answer apply to Tax year 2018, too? My wife had a small 401(k) through her work and they cut us a check minus the forfeiture amount and federal withholding. Second part to this question, since she had more contributions between January 2019 and today (almost tax day 2019) will I need to add this or wait until next year for a 1099R from this former employee (she quit in February 2018)?