We’ve been asked this question several times over the last week. The Williams College Libraries website gives the answer.
The following applies,
When paraphrasing, APA style does not require page numbers in the in-text citation. However, authors are encouraged to include page numbers if it will help the reader locate the relevant information in longer texts. Consult with your professor regarding the need for page numbers for paraphrased information.
If the reference is to an exact quotation, the author, year and page number must be included. The page number can be given in parentheses at the end of the exact quotation or incorporated into the in-text citation. Newman (1994) concluded “sibling conflict is so common that its occurence is taken for granted” (p. 123). Such findings have prompted one researcher to conclude, “Sibling conflict is so common that its occurrence is taken for granted” (Newman, 1994, p. 123).
For exact quotations from sources without page numbers, use paragraph numbers, if available. If the paragraphs are not numbered, but there are headings, use the heading name and count the number of paragraphs after the heading to the paragraph containing the quotation. (Publication Manual, Chapter 6.05, p. 171)
(Smith, 2003, para. 1)
(Greene, 2003, Discussion, para. 4)